ALBERT

Description:    The effect of strain accumulation in the InAs/In x Ga 1− x As quantum dots (QDs) system was studied in this work. It was found that strain in the In x Ga 1− x As layer accumulation in the QD layer. This effect resulted in a dramatic reduction of growth mode transition thickness of the QD layer. For InAs/In 0.25 Ga 0.75 As QDs, critical thickness is measured to be as low as 1.08 ML. The experimental results in this work highlight the importance of strain accumulation in the design and fabrication of QD-based devices with metamorphic buffer layer involved. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6482-1 Authors Lu Wang, National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China Meicheng Li, School of Renewable Energy, North China Electric Power University, Beijing, 102206 China Wenxin Wang, National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China Haitao Tian, National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China Zhigang Xing, National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China Min Xiong, School of Material Science and Technology, Harbin Institute of Technology, Harbin, China Liancheng Zhao, School of Material Science and Technology, Harbin Institute of Technology, Harbin, China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The strong influence of laser polarization on the orientation and shape of femtosecond-laser-induced self-organized nanostructures (‘ripples’, LIPSS) still constitutes an open question, taking into account that the laser electric field is present only at the first step of electronic excitation. Based on the explanation of similar structures generated during ion sputtering, we present a theoretical model indicating a possible explanation for this phenomenon. Our model shows that a directional asymmetry in the pattern can result from a spatial asymmetry of the initial excitation, induced e.g. by a corresponding distribution of excited-electron kinetic energies. Numerical simulation of this model yields typical patterns which are compared to experimental observations under appropriate conditions. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6472-3 Authors Juergen Reif, Experimental Physics II/Materials Science, Brandenburgische Technische Universität (BTU) Cottbus, Universitätsstr. 1, 03046 Cottbus, Germany Olga Varlamova, Experimental Physics II/Materials Science, Brandenburgische Technische Universität (BTU) Cottbus, Universitätsstr. 1, 03046 Cottbus, Germany Sergej Varlamov, Statistical Physics and Nonlinear Dynamics, Brandenburgische Technische Universität (BTU) Cottbus, Universitätsstr. 1, 03046 Cottbus, Germany Michael Bestehorn, Statistical Physics and Nonlinear Dynamics, Brandenburgische Technische Universität (BTU) Cottbus, Universitätsstr. 1, 03046 Cottbus, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The preparation of chlorine-, bromine-, and iodine-terminated silicon surfaces (Si(111):Cl, Br, and I) using atomically flat Si(111)-(1×1):H is described. The halogenated surfaces were obtained by photochemically induced radical substitution reactions with the corresponding dihalogen in a Schlenk tube by conventional inert gas chemistry. The nucleophilic substitution of the Si-Cl functionality with the Grignard reagent (CH 3 MgCl) resulted in the unreconstructed methylated Si(111)-(1×1):CH 3 surface. The halogenated and methylated silicon surfaces were characterized by Fourier transform infrared (FTIR) spectroscopy and laser-induced desorption of monolayers (LIDOM). Calibration of the desorption temperature via analysis of time-of-flight (TOF) distributions as a function of laser fluence allowed the determination of the originally emitted neutral fragments by TOF mass spectrometry using electron-impact ionization. The halogens were desorbed atomically and as SiX n (X = Cl, Br) clusters. The methyl groups mainly desorbed as methyl and ethyl fragments and a small amount of + SiCH 3 . Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6483-0 Authors Nils Salingue, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg, Germany Peter Hess, Institute of Physical Chemistry, University of Heidelberg, 69120 Heidelberg, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We have demonstrated spatially selective modification of the magnetic properties of transparent iron-oxide-doped glass by femtosecond- (fs-) laser irradiation and subsequent annealing. A near-infrared fs-laser beam with a wavelength of 775 nm was focused 1 mm below the surfaces of glass samples. This produces absorption peaks due to the formation of hole-trap centers in the irradiated region. Transparency was recovered after annealing at 450°C. A ferrimagnetic component was observed in the M–H curve even at room temperature, whereas the diamagnetic component dominated in the M–H curve of the as-prepared glass sample. This indicates that fs-laser irradiation enhanced the magnetization in the irradiated area. The irradiated and annealed glass sample also exhibited superparamagnetic blocking in the temperature dependence of the magnetization with a blocking temperature higher than room temperature. This change in magnetism is presumably due to local crystallization of ferrimagnetic nanoparticles, such as magnetite, induced by fs-laser irradiation and annealing. The magnetic and optical properties of glass that had been annealed but not irradiated by a fs-laser beam remained unchanged. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6485-y Authors Seisuke Nakashima, RIKEN—Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan Koji Sugioka, RIKEN—Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan Katsumi Midorikawa, RIKEN—Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In this paper, we demonstrate that cubic gadolinium oxide is paramagnetic and follows the Curie–Weiss law from 20 K to room temperature for particles size comprised between 3.5 and 60 nm. The largest particles (60 nm) possess the macroscopic behaviour of Gd oxide with a Néel temperature, T N , close to 18 K (Gd oxide is antiferromagnetic below T N , paramagnetic above). Then size-induced effects can be encountered only for particles smaller than 60 nm. We find that the finite-size scaling model used for describing the size evolution of the antiferro/paramagnetic transition is valid for sizes comprised between 3.5 and 35 nm with parameters in excellent agreement with those usually found for antiferromagnetic materials. The correlation length (3.6 nm) is of the order of magnitude of a few lattice parameters and the critical exponent λ is found equal to 1.3, a value very close to that predicted by the three dimensional Heisenberg model ( λ =1.4). Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6492-z Authors B. Mutelet, MATEIS, UMR 5510 CNRS, Université de Lyon, INSA-Lyon, 20 av. Albert Einstein, 69621 Villeurbanne Cedex, France N. Keller, GEMAC, UMR 8635 CNRS, Université de Versailles-St-Quentin, 45, avenue des Etats-Unis, 78035 Versailles Cedex, France S. Roux, UTINAM, UMR 6213 CNRS, Université de Franche-Comté, 25030 Besanon Cedex, France M. A. Flores-Gonzales, LPCML, Université de Lyon, Université Claude Bernard, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France F. Lux, LPCML, Université de Lyon, Université Claude Bernard, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France M. Martini, MATEIS, UMR 5510 CNRS, Université de Lyon, INSA-Lyon, 20 av. Albert Einstein, 69621 Villeurbanne Cedex, France O. Tillement, LPCML, Université de Lyon, Université Claude Bernard, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France C. Billotey, LPCML, Université de Lyon, Université Claude Bernard, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France M. Janier, LPCML, Université de Lyon, Université Claude Bernard, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France C. Villiers, INSERM U823, Institut Albert Bonniot, Rond Point de la Chantourne, 38574 La Tronche, France Ghenadie Novitchi, Laboratoire des Multimatériaux et Interfaces, Université de Lyon, Université Claude Bernard, 3 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France Dominique Luneau, Laboratoire des Multimatériaux et Interfaces, Université de Lyon, Université Claude Bernard, 3 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France P. Perriat, MATEIS, UMR 5510 CNRS, Université de Lyon, INSA-Lyon, 20 av. Albert Einstein, 69621 Villeurbanne Cedex, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Surface ablation of a dielectric material (fused silica) by single femtosecond pulses is studied as a function of pulse duration (7–450 fs) and applied fluence ( F th 〈 F 〈10 F th ). We show that varying the pulse duration gives access to high selectivity (with resolution ∼10 nm) for axial removal of matter but does not influence the transverse ablation selectivity, which only depends on the normalized applied fluence F / F th . The ablation efficiency is shown to be inversely dependent on the pulse duration and saturates with respect to the applied fluence earlier at ultra-short pulse durations (≤30 fs). The deduced optimal fluence F opt corresponding to the highest ablation efficiency for each pulse width defines two regimes of laser application. Below F opt , the removed material depth can be accurately adjusted in a large range (∼40–200 nm) as a function of the applied fluence and the morphology of the ablated pattern almost reproduces the Gaussian beam distribution. Above F opt , the material removal depth tends to saturate and the morphology of the ablated pattern evolves to a top-hat distribution. The coupled evolution of depth and morphology is related to the dynamics of formation of dense plasma at the surface of the material, acting as an ultra-fast optical shutter. Content Type Journal Article Pages 1-11 DOI 10.1007/s00339-011-6469-y Authors O. Utéza, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France N. Sanner, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France B. Chimier, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France A. Brocas, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France N. Varkentina, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France M. Sentis, Laboratoire LP3, UMR 6182 CNRS-Aix-Marseille Université, C. 917, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France P. Lassonde, Energie, Matériaux et Télécommunications, INRS, 1650 Boulevard Lionel Boulet, Varennes, Québec J3X 1S2, Canada F. Légaré, Energie, Matériaux et Télécommunications, INRS, 1650 Boulevard Lionel Boulet, Varennes, Québec J3X 1S2, Canada J. C. Kieffer, Energie, Matériaux et Télécommunications, INRS, 1650 Boulevard Lionel Boulet, Varennes, Québec J3X 1S2, Canada Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    An energy source produced by a TEA CO 2 laser operated at 10.6 μm primarily was considered as a key essential in this paper to describe the energy conversion process in air-breathing laser propulsion in the round. Some secondary factors were ignored when three independent modules, a ray transmission module, an energy source term module and a fluid mechanics module, were established by a simultaneous laser radiation transportation equation and a fluid mechanics equation set-up. The incident laser beam after being reflected by the optical system or transmitted by it was simulated based on a certain geometrical optics method named ray tracing. Thus, coherent superimposition could be avoided when describing the laser beam focusing process, and so could the solving process of the laser wave equation at the non-paraxial condition. The calculated results were in good agreement with those of theoretical analysis and experiments. Content Type Journal Article Pages 1-8 DOI 10.1007/s00339-011-6479-9 Authors Yanji Hong, Academy of Equipment Command & Technology, Post Box 3380-86, Huairou District, Beijing, 101416 China Junling Song, Academy of Equipment Command & Technology, Post Box 3380-86, Huairou District, Beijing, 101416 China Cunyan Cui, Academy of Equipment Command & Technology, Post Box 3380-86, Huairou District, Beijing, 101416 China Qian Li, Academy of Equipment Command & Technology, Post Box 3380-86, Huairou District, Beijing, 101416 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Understanding the mechanical properties of ancient paintings is a major issue for conservation and restoration. One strategy is to measure the mechanical properties of reconstructed paints: however, the aging process is poorly known, so it is also desirable to measure mechanical properties directly on ancient paint samples. Using nanoindentation, we have characterized submillimetric samples recovered from restoration of two Van Gogh paintings and compared the results with reconstructed paint samples. We demonstrate that the reduced modulus and hardness of historical paints can be measured at a very local scale, even differentiating between each paint layer. Our reconstructed paint samples exhibit elastic moduli comparable to values of the literature, but the values measured on the two 19th century paint samples are found to be significantly larger. Similarly, the compositional dependence of the elastic modulus is consistent with literature results for our reconstructed samples while our preliminary results for ancient samples do not readily fall into the same pattern. These results all point out to a significant impact of long term aging, in a manner which is difficult to predict in our present state of understanding. They demonstrate that nanoindentation is a very adequate tool to improve our knowledge of art paint mechanics and aging. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6486-x Authors Johanna Salvant, Laboratoire du Centre de Recherche et de Restauration des Musées de France (C2RMF), CNRS UMR 171, Palais du Louvre, 14, Quai François Mitterrand, Paris, 75001 France Etienne Barthel, Laboratoire CNRS/Saint-Gobain “Surface du Verre et Interfaces”, UMR 125, 39, Quai Lucien Lefranc, BP 135, Aubervilliers Cedex, 93303 France Michel Menu, Laboratoire du Centre de Recherche et de Restauration des Musées de France (C2RMF), CNRS UMR 171, Palais du Louvre, 14, Quai François Mitterrand, Paris, 75001 France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The effect of HfO 2 on phase change characteristics of Sb 2 Te 3 films for phase change memory (PCM) applications was investigated by in situ temperature dependence of electrical resistance measurement, X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. It is shown that HfO 2 inhibited the crystallization of the amorphous Sb 2 Te 3 films, which improved the long-term stability of metastable amorphous phase. Memory devices based on Sb 2 Te 3 –HfO 2 composite films with HfO 2 concentrations of 10 at.% and 15 at.% were successfully fabricated and characterized. The 15 at.% HfO 2 -based memory device exhibited lower reset voltage and power consumption compared with the 10 at.% HfO 2 - and Ge 2 Sb 2 Te 5 -based ones. The endurances exceeded 1.6×10 5 and 2.2×10 5 SET–RESET cycles for 10 at.% and 15 at.% HfO 2 -based memory devices, respectively, and the resistance ratio between RESET and SET states achieved two orders of magnitude for both memory devices. The Sb 2 Te 3 –HfO 2 composite films, especially with HfO 2 concentration of 15 at.%, could be one of the most promising materials for application in PCM devices. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6478-x Authors Yegang Lu, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Sannian Song, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Zhitang Song, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Kun Ren, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Bo Liu, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Songlin Feng, State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai, 200050 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We investigated the ejection dynamics of triazene polymer layers in the thickness range of 40 nm to 600 nm upon nanosecond laser ablation at a wavelength of 532 nm. The ablation is due to laser-induced thermal degradation of a small part of the polymer in contact with the silicon substrate. The subsequent dynamics of the flying polymer layer are measured with sub-nanosecond time resolution. The evaluation of the initial velocity for different film thicknesses gives insight into the energy transfer process during the acceleration of the films. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6500-3 Authors P. Frank, University of Konstanz, 78457 Konstanz, Germany J. Shaw-Stewart, Laboratory for Functional Polymers, EMPA, Swiss Federal Laboratories for Material Testing and Research, Überlandstrasse 129, 8600 Dübendorf, Switzerland T. Lippert, General Energy Research Department, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland J. Boneberg, University of Konstanz, 78457 Konstanz, Germany P. Leiderer, University of Konstanz, 78457 Konstanz, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Spontaneous nanostructure formations on roughened and smooth silicon surface by the femtosecond laser irradiation with the repetition rate of 100 kHz were systematically studied. In addition to the widely accepted so-called coarse ripple, which has the period analogous to the wavelength of the laser beam and aligns perpendicularly to the electric field of the incident laser beam, the ripple which has the period similar to the wavelength of the incident laser beam but aligns parallel to the electric field of the laser beam was observed on the roughened surface for the lower fluence and the higher number of pulse irradiation. Furthermore, the ensemble of dots formed by the enhancement of the local electric field was found on the roughened surface. This structure is preferentially formed around the scratches aligned perpendicularly to the electric field of the laser beam. These novel nanostructures are considered to be peculiar to the femtosecond laser irradiation and open the possibilities for precise control of the spontaneous nanostructure formation by femtosecond laser irradiation. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6490-1 Authors Takuro Tomita, Department of Ecosystem Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Ryota Kumai, Department of Ecosystem Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Hidenori Nomura, Department of Ecosystem Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Shigeki Matsuo, Department of Ecosystem Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Shuichi Hashimoto, Department of Ecosystem Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Ken Morita, Center for Frontier Research of Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Toshiro Isu, Center for Frontier Research of Engineering, The University of Tokushima, Tokushima, 770-8506 Japan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We present a study of the temperature non-homogeneities induced by millisecond laser annealing in advanced CMOS technologies at die level. Because of the design, the device layout at the wafer surface introduces during this anneal significant spatial variations of optical absorption and heat transfer that can induce temperature non-uniformities over the die, often called ‘pattern effects’. These temperature variations are becoming a major issue, since they are the origin of significant device properties dispersion. A complete optical and thermal simulation set has been developed to estimate the temperature variations induced by the topologies at the wafer surface during the laser anneal process. The modelling has been validated by either a comparison with another software or reflectometry and electrical measurements on real structures. This work demonstrates that the temperature variations are caused either by optical coupling or by thermal properties dispersion present at the wafer surface at the anneal step. Finally, we demonstrate that the impact of the thin-film interferences and diffraction phenomena is the critical issue for these pattern effects. Content Type Journal Article Pages 1-11 DOI 10.1007/s00339-011-6467-0 Authors A. Colin, STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex, France P. Morin, STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex, France F. Cacho, STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex, France H. Bono, LETI, CEA-Grenoble, 17 Rue des Martyrs, 38054 Grenoble Cedex 9, France R. Beneyton, STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex, France D. Mathiot, InESS, CNRS and Université de Strasbourg, BP 20 CR, 23 rue de Loess, 67037 Strasbourg Cedex 2, France E. Fogarassy, InESS, CNRS and Université de Strasbourg, BP 20 CR, 23 rue de Loess, 67037 Strasbourg Cedex 2, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    A micro-crack in silicon was experimentally investigated by using a combination of transmission electron microscopy and geometric phase analysis. The strain fields of the crack tip, with scales of a few tens of nanometers, were mapped. The crack tip dislocation emission and stress relief by dislocation generation around a crack tip can be proved. And, the strain field of an edge dislocation was compared with the Peierls–Nabarro dislocation model at the scale of a dislocation width. We show that the Peierls–Nabarro model is the appropriate theoretical model to describe the deformation fields of the dislocation core. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6488-8 Authors C. W. Zhao, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China Y. M. Xing, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China P. C. Bai, College of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot, 010051 China J. J. Li, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China Q. L. Liu, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China Y. G. Du, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China M. H. Liu, College of Science, Inner Mongolia University of Technology, Hohhot, 010051 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Thin films of the n-type, organic semiconductor PDI-8CN 2 were thermally evaporated on two different dielectric surfaces and their optical and morphological properties investigated using Variable Angle Spectroscopic Ellipsometry (VASE) and Atomic Force Microscopy (AFM), respectively. The two dielectric surfaces used were SiO 2 and a plasma polymer derived from the non-synthetic monomer linalyl acetate. The characterisations were performed in order to assess the viability of plasma polymerised linalyl acetate (PLA) thin films as dielectric layers in future Organic Field-Effect Transistor (OFET) devices. These studies resulted in determination of the optical profiles (refractive index and extinction coefficient) in the UV-Vis band of PDI-8CN 2 grown on SiO 2 and an observation of uniaxial anisotropy in the organic semiconductor. This information is useful for the design of opto-electronic devices using PDI-8CN 2 layers. Variations in morphological properties and small variations optical properties were found when the PDI-8CN 2 films were grown on PLA layers, and attributed to the change in surface chemistry between dielectrics. Content Type Journal Article Pages 1-8 DOI 10.1007/s00339-011-6487-9 Authors L. J. Anderson, Electronic Materials Research Lab, School of Engineering and Physical Sciences, James Cook University, Townsville, QLD 4811 Australia M. V. Jacob, Electronic Materials Research Lab, School of Engineering and Physical Sciences, James Cook University, Townsville, QLD 4811 Australia M. Barra, CNR-SPIN and Department of Physics Science, University of Naples Federico II, Piazzale Tecchio 80125 Naples, Italy F. V. Di Girolamo, CNR-SPIN and Department of Physics Science, University of Naples Federico II, Piazzale Tecchio 80125 Naples, Italy A. Cassinese, CNR-SPIN and Department of Physics Science, University of Naples Federico II, Piazzale Tecchio 80125 Naples, Italy Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Thermophysical properties of liquid alloys are usually difficult to measure, especially for high melting point and reactive alloys. In this work, the surface tensions of superheated and undercooled liquid Ti 55 Al 45 , Ti 50 Al 45 Nb 5 and Ti 45 Al 45 Nb 10 alloys are determined by using oscillating drop method under electromagnetic levitation state. The experimental results of Ti–Al and Ti–Al–Nb alloys display linear temperature dependence. The maximum undercoolings of 259 (0.143 T L ), 268 (0.146 T L ) and 275 K (0.147 T L ) are respectively achieved for these three alloys. Furthermore, the viscosities of liquid Ti 55− x Al 45 Nb x alloys are also derived from the experimental results. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6491-0 Authors K. Zhou, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710072 People’s Republic of China H. P. Wang, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710072 People’s Republic of China J. Chang, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710072 People’s Republic of China B. Wei, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710072 People’s Republic of China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Hierarchical ZnO (zinc oxide) nanostructures composed with nano-sheet and micro-flower structures (made from the nano-sheet) have been generated on tinfoil substrate via a chemical bath deposition process. Benefiting from an inherent distinct lattice constant compared with commonly used glass or other kinds of substrate, the tinfoil substrate played an important role on the formation of the hierarchical ZnO nanostructures. The resulting hierarchical ZnO surface shows excellent superhydrophobicity and extremely low water rolling angle after being modified with spin coating Teflon. The flexible and superhydrophobic characteristics of such fabricated substrate will be beneficial for applications requiring bendable and lightweight superhydrophobic substrates. In addition, the multifunctional properties of ZnO nanostructures are expected to broaden the applications to electronic and optical applications. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6493-y Authors Jun Wu, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096 P.R. China Jun Xia, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096 P.R. China Chen Jing, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096 P.R. China Wei Lei, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096 P.R. China Bao-ping Wang, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096 P.R. China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Thin films of silicon carbide (SiC) have been prepared by means of pulsed laser deposition (PLD) on sapphire (Al 2 O 3 ) and Si(100) substrates with a Nd-YAG laser 1064 nm. We achieved the growth of cubic silicon carbide (3C-SiC) films at the temperatures of 650°C from a SiC target in vacuum. The as-deposited films are morphologically and structurally characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). The use of off-axis PLD method placing the sample at 90° with respect to the target leads to a good quality smooth film. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6494-x Authors G. Monaco, LUXOR Laboratory, CNR-IFN, Via Trasea 4, Padova, Italy D. Garoli, Physical Department “G. Galilei”, University of Padova, Via Marzolo 8, Padova, Italy M. Natali, CNR-ICIS Corso Stati Uniti 4, Padova, Italy M. G. Pelizzo, LUXOR Laboratory, CNR-IFN, Via Trasea 4, Padova, Italy P. Nicolosi, LUXOR Laboratory, CNR-IFN, Via Trasea 4, Padova, Italy Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    GaN is a promising material not only for electronic devices but also for photocatalysts. Synthesis of GaN nanocrystal is a key issue to improve performance for these applications. In the present study, GaN nanocrystallites have been synthesized by pulsed laser ablation (PLA), where safe and inactive pure N 2 gases were used as reactive background gases. The third harmonics beam of a Q -switched Nd:YAG laser (355 nm, 10 mJ/pulse, 4 J/(cm 2 pulse)) was used to ablate a sintered high purity GaN target. The deposition substrates were not heated. It was clarified that the formed GaN nanoparticles contained a hexagonal system with the wurtzite structure. The diameter of the nanocrystallites was about 10 nm, and showed only little dependence on the background gas pressure, while the porosity of the assembly of nanocrystallites and content of GaN nanocrystallites in the assembly increased with background gas pressure. Highly porous nanometer-sized GaN film obtained at higher gas pressure is considered to be candidate structures for the photocatalysts. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6438-5 Authors Takehito Yoshida, Department of Mechanical Engineering, Anan National College of Technology, Anan, Tokushima 774-0017, Japan Soichiro Kakumoto, Department of Physics, Konan University, Kobe, 658-8501 Japan Akira Sugimura, Department of Physics, Konan University, Kobe, 658-8501 Japan Ikurou Umezu, Department of Physics, Konan University, Kobe, 658-8501 Japan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Laser Spinning is a new technique that has been shown to quickly produce amorphous inorganic nanofibers from bulk material under atmospheric conditions. This technique employs a high power laser to melt a small volume of the precursor material while a supersonic gas jet provokes its rapid elongation and cooling, producing long micro- and nanofibers within a range of diameters. In this work, the quantity of the fibers produced and the distribution of their diameters are measured and statistically analyzed for different operating conditions. The advance speed of the laser beam over the precursor material is experimentally demonstrated to be the most influencing factor on the diameter of the fibers. Other variables of the process, such as assist gas pressure, were found to have less influence. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6415-z Authors O. Dieste, Applied Physics Dept., Universidade de Vigo, EEI, Campus as Lagoas, Vigo, Spain F. Quintero, Applied Physics Dept., Universidade de Vigo, EEI, Campus as Lagoas, Vigo, Spain J. Pou, Applied Physics Dept., Universidade de Vigo, EEI, Campus as Lagoas, Vigo, Spain F. Lusquiños, Applied Physics Dept., Universidade de Vigo, EEI, Campus as Lagoas, Vigo, Spain A. Riveiro, Applied Physics Dept., Universidade de Vigo, EEI, Campus as Lagoas, Vigo, Spain Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The resonant transmission peaks in the asymmetric and symmetric multilayer narrowband transmission filters are theoretically investigated based on the transfer matrix method. In an asymmetric filter there exists only one resonant peak within the photonic band gap, and its position can be changed when the design wavelength is varied. In a symmetric filter, it is found that there are two resonant peaks. Using Bloch wave approximation, an investigation of these two resonant peaks has been made, and they are shown to correspond to the symmetric and antisymmetric field solutions in the defect layer. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6434-9 Authors Tsung-Wen Chang, Graduate Institute of Electro-Optical Engineering, Chang Gung University, Tao-Yuan, 333 Taiwan Tzong-Jer Yang, Department of Electrical Engineering, Chunghua University, Hsinchu, 300 Taiwan Zheng-Hui Wang, Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, 116 Taiwan Chien-Jang Wu, Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, 116 Taiwan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Dispersion properties, birefringence and confinement loss between the circular air-hole photonic crystal fiber (CAHPCF) and rotational elliptical air-hole photonic crystal fiber (REAHPCF) are investigated numerically by means of a plane-wave expansion method and a finite element method. Results show that the performances of REAHPCF on flatter dispersion curve, single mode, high birefringence and low confinement loss is better than that of CAHPCF. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6426-9 Authors Tzong-Jer Yang, Department of Electrical Engineering, Chung Hua University, Hsinchu, 300 Taiwan, ROC Yuan-Fong Chau, Department of Electronic Engineering, Ching Yun University, Jung-Li, 320 Taiwan, ROC Han-Hsuan Yeh, Department of Electronic Engineering, Ching Yun University, Jung-Li, 320 Taiwan, ROC Zheng-Hong Jiang, Department of Electronic Engineering, Ching Yun University, Jung-Li, 320 Taiwan, ROC Yao-Wei Huang, Graduate Institute of Applied Physics, National Taiwan University, Taipei, Taiwan, ROC Kuang-Yu Yang, Graduate Institute of Applied Physics, National Taiwan University, Taipei, Taiwan, ROC Din Ping Tsai, Graduate Institute of Applied Physics, National Taiwan University, Taipei, Taiwan, ROC Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    UV-absorbing silicon monoxide (SiO x , x ≈1) thin films on fused silica substrates are irradiated by an ArF excimer laser (wavelength 193 nm) in the sub-ablation threshold regime. Multi-pulse irradiation of films with ∼200-nm thickness at a fluence of about 100 mJ/cm 2 leads to a significant increase of the UV transmission, indicating the oxidation of SiO x to SiO 2 . The quality of the obtained films after this laser annealing process depends on the oxygen content of the environment. Irradiation in air at atmospheric pressure leads to the formation of sub-micron-sized oxide particles on top of the film. Structured illumination is applied either to form areas of the film with changed transmission and refractive index, or for the formation of regular particle patterns with sub-micron periods. These processes can be utilized for the fabrication of phase masks or for various types of surface functionalization. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6451-8 Authors J. Richter, Laser-Laboratorium Göttingen e.V., Hans-Adolf-Krebs-Weg 1, 37077 Göttingen, Germany J. Meinertz, Laser-Laboratorium Göttingen e.V., Hans-Adolf-Krebs-Weg 1, 37077 Göttingen, Germany J. Ihlemann, Laser-Laboratorium Göttingen e.V., Hans-Adolf-Krebs-Weg 1, 37077 Göttingen, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Hierarchical ZnO microrods have been prepared by cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal process at low temperature. Sheetlike or fluffy ZnO nanostructures have been developed in a large density on the surface of the microrods. The ZnO cores grow preferentially along [001]; the nanosheets are single crystalline and grow in two dimensions along the [001] and [120] directions. The formation of hierarchical structures has been attributed to the presence of CTAB in the solution, which facilitates the secondary nucleation and growth. The nanosheet-covered hierarchical microrods have been analyzed by Raman and photoluminescence spectroscopy, and they exhibit a blue emission at 465 nm and a strong orange emission at 640 nm. Photocatalytic activities of the products have been examined, and the nanosheet-covered hierarchical microrods display the best activity in photodegradation of phenol due to their unique surface features and high surface area. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6452-7 Authors Yongqiang Yang, Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, 321004 China Gaohui Du, Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, 321004 China Xin Xin, Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, 321004 China Bingshe Xu, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The inverted polymer:fullerene solar cells with structure of ITO/TiO 2 /P3HT:PCBM/MoO 3 /Al have been fabricated, where P3HT and PCBM stand for poly (3-hexylthiophene) and [6,6]-phenyl C 61 -butyric acid methyl ester, respectively. It is discovered that the P3HT:PCBM blend film manipulated into the improved stratification structure, characterized as P3HT crystallite-rich zone close to the top surface and PCBM constituent-rich zone adjacent to the bottom surface, can offer nearly the same power conversion efficiency of solar cell, compared to the one grown into the bulk heterojunction structure, characterized as the bicontinuous interpenetrating network of P3HT and PCBM. We provide an alternative insight to the morphology control of inverted polymer:fullerene solar cells. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6448-3 Authors Wei Quan, Institute of Polymer Science and Engineering, School of Chemical Engineering, Hebei University of Technology, Tianjin, 300130 People’s Republic of China Cuiran Cheng, Institute of Polymer Science and Engineering, School of Chemical Engineering, Hebei University of Technology, Tianjin, 300130 People’s Republic of China Jinsuo Liu, Institute of Polymer Science and Engineering, School of Chemical Engineering, Hebei University of Technology, Tianjin, 300130 People’s Republic of China Jidong Zhang, State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022 Jilin, People’s Republic of China Donghang Yan, State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022 Jilin, People’s Republic of China Dashan Qin, Institute of Polymer Science and Engineering, School of Chemical Engineering, Hebei University of Technology, Tianjin, 300130 People’s Republic of China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Transparent 90GeS 2 ⋅10Ga 2 S 3 (G10) chalcogenide glass-ceramics containing β -GeS 2 nanocrystals was successfully fabricated through controllable crystallization based on the knowledge of its nucleation-rate-like curve. Using the conventional Z-scan method, both large spectral dependence and crystallinity dependence of optical nonlinear parameters were learned under the excitation of different wavelengths that in proximity of the half-bandgap. In particular, a large value of figure of merit (FOM≈11.64) was obtained in the crystallized sample after the heat-treatment at 466°C for 40 h. Although it is not a straightforward process to select an appropriate medium for a specific application, this work opens a new way to construct suitable optical nonlinear properties (e.g., large FOM) though modifying the microstructure of chalcogenide glass-ceramics. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6454-5 Authors Changgui Lin, College of Materials Science & Chemical Engineering, Ningbo University, Ningbo, 315211 China Laurent Calvez, Laboratoire des Verres et Céramiques, UMR-CNRS 6226, Sciences chimiques de Rennes, Université de Rennes 1, 35042 Rennes Cedex, France Lei Ying, College of Information Science and Engineering, Ningbo University, Ningbo, 315211 China Feifei Chen, College of Information Science and Engineering, Ningbo University, Ningbo, 315211 China Bao’an Song, College of Information Science and Engineering, Ningbo University, Ningbo, 315211 China Xiang Shen, College of Information Science and Engineering, Ningbo University, Ningbo, 315211 China Shixun Dai, College of Information Science and Engineering, Ningbo University, Ningbo, 315211 China Xianghua Zhang, Laboratoire des Verres et Céramiques, UMR-CNRS 6226, Sciences chimiques de Rennes, Université de Rennes 1, 35042 Rennes Cedex, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The combination of high-field physics with nano-plasmonics has proven to be feasible in producing high harmonics of intense laser radiation from noble gases, assisted by the field-enhancement effect in the proximity of metallic nano-antennas. However, the intensity region where harmonics can be generated without irreversible damage to these delicate structures is rather narrow. We explore the damage threshold of gold targets that exhibit regular structures on a nanoscopic scale, either explicitly resonant to the used laser frequency, or off-resonance. These are compared to values for bulk material in order to gain insight into the role of plasmonic resonances in the response of solid targets on intense laser radiation. We find that the presence of such a resonance lowers the threshold fluence (J/cm 2 ) where global structural damage sets in by about an order of magnitude. Statistical deviations either in local pulse energy of the damage inducing laser radiation or in the exact resonance behaviour of singular structures prove to be limited. These results should serve as a guideline for future experiments working near the damage threshold of more sophisticated antenna designs. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6449-2 Authors C. Kern, Institut für Optik und Quantenelektronik, Physikalisch-Astronomische Fakultät, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany M. Zürch, Institut für Optik und Quantenelektronik, Physikalisch-Astronomische Fakultät, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany J. Petschulat, Institut für Angewandte Physik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany T. Pertsch, Institut für Angewandte Physik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany B. Kley, Institut für Angewandte Physik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany T. Käsebier, Institut für Angewandte Physik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany U. Hübner, Institut für Photonische Technologien, Albert-Einstein-Straße 9, 07745 Jena, Germany C. Spielmann, Institut für Optik und Quantenelektronik, Physikalisch-Astronomische Fakultät, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    This paper experimentally compares the intensity and phase detection sensitivities of grating coupling surface plasmon resonance (SPR). A simple air-heating method is proposed to implement tiny refractive index changes. An electro-optic heterodyne interferometer is used to obtain both the intensity and phase curves of the grating coupling SPR device. The transient reflectivity and phase curves during the heating process are recorded. The result shows that the phase detection sensitivity is much better than that of the intensity by an order of magnitude. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6419-8 Authors Wen-Kai Kuo, Department of Electro-Optics Engineering, National Formosa University, 64 Wenhua Rd., Huwei, Yunlin 63208, Taiwan, ROC Chih-Hao Chang, Department of Electro-Optics Engineering, National Formosa University, 64 Wenhua Rd., Huwei, Yunlin 63208, Taiwan, ROC Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Thin films of fullerenes (C 60 ) were deposited onto silicon using matrix-assisted pulsed laser evaporation (MAPLE). The deposition was carried out from a frozen homogeneous dilute solution of C 60 in anisole (0.67 wt%), and over a broad range of laser fluences, from 0.15 J/cm 2 up to 3.9 J/cm 2 . MAPLE has been applied for deposition of fullerenes for the first time and we have studied the growth of thin films of solid C 60 . The fragmentation of C 60 fullerene molecules induced by ns ablation in vacuum of a frozen anisole target with C 60 was investigated by matrix-assisted laser desorption/ionization (MALDI). Our findings show that intact fullerene films can be produced with laser fluences ranging from 0.15 J/cm 2 up to 1.5 J/cm 2 . Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6432-y Authors S. Canulescu, Department of Photonics Engineering, Risø Campus, Technical University of Denmark, 4000 Roskilde, Denmark J. Schou, Department of Photonics Engineering, Risø Campus, Technical University of Denmark, 4000 Roskilde, Denmark S. F. Nielsen, Materials Research Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark, 4000 Roskilde, Denmark Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The recent demonstration of thermal conductivity of rough electrolessly etched Si nanowire (Hochbaum et al., Nature, 451:163, 2008 ) attracted a lot of interest, because it could not be explained by the existing theory; thermal conductivity of rough Si nanowires falls below the boundary scattering of the thermal conductivity. However, nanoscale pores presented in the nanowires (Hochbaum et al., Nano Letters, 9:3550–3554, 2009 ) hinder one to be fully convinced that the surface roughness solely made a contribution to the significant reduction in thermal conductivity. In this study, we synthesized vapor–liquid–solid (VLS) grown rough Si 1− x Ge x nanowire and measured and theoretically simulated thermal conductivity of the nanowire. The thermal conductivity of rough Si 0.96 Ge 0.04 nanowire is an order of magnitude lower than that of bulk Si 0.96 Ge 0.04 and around a factor of four times lower than that of smooth Si 0.96 Ge 0.04 nanowire. This significant reduction could be explained by the fact that the surface roughness scatters medium-wavelength phonons, whereas the long-wavelength phonons are scattered by phonon boundary scattering, and the short-wavelength phonons are scattered by alloy scattering. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6475-0 Authors Hyoungjoon Kim, School of Mechanical Engineering, Yonsei University, Seoul, 120-749 Korea Yong-Hee Park, Department of Materials Science and Engineering, Yonsei University, Seoul, 120-749 Korea Ilsoo Kim, Department of Materials Science and Engineering, Yonsei University, Seoul, 120-749 Korea Jungwon Kim, School of Mechanical Engineering, Yonsei University, Seoul, 120-749 Korea Heon-Jin Choi, Department of Materials Science and Engineering, Yonsei University, Seoul, 120-749 Korea Woochul Kim, School of Mechanical Engineering, Yonsei University, Seoul, 120-749 Korea Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Highly ordered NiO coated Si nanowire arrays are fabricated as electrode materials for electrochemical supercapacitors (ES) via depositing Ni on electroless-etched Si nanowires and subsequently annealing. The electrochemical tests reveal that the constructed electrode has superior electrical conductibility and more active sites per unit area for chemical reaction processes, thereby possessing good cycle stability, high specific capacity, and low internal resistance. The specific capacity is up to 787.5 F g −1 at a discharge current of 2.5 mA and decreases slightly with 4.039% loss after 500 cycles, while the equivalent internal resistance is ∼3.067 Ω. Owing to its favorable electrochemical performance, this ordered hybrid array nanostructure is a promising electrode material in future commercial ES. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6412-2 Authors Fang Lu, Laboratory for Quantum Engineering and Micro-Nano Energy Technology and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan, 411105 P.R. China Mengchun Qiu, Laboratory for Quantum Engineering and Micro-Nano Energy Technology and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan, 411105 P.R. China Xiang Qi, Laboratory for Quantum Engineering and Micro-Nano Energy Technology and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan, 411105 P.R. China Liwen Yang, Laboratory for Quantum Engineering and Micro-Nano Energy Technology and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan, 411105 P.R. China Jinjie Yin, Laboratory for Quantum Engineering and Micro-Nano Energy Technology and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan, 411105 P.R. China Guolin Hao, Laboratory for Quantum Engineering and Micro-Nano Energy Technology and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan, 411105 P.R. China Xiang Feng, Laboratory for Quantum Engineering and Micro-Nano Energy Technology and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan, 411105 P.R. China Jun Li, Laboratory for Quantum Engineering and Micro-Nano Energy Technology and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan, 411105 P.R. China Jianxin Zhong, Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan, 411105 P.R. China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In this paper we report a simple method that enables the easy fabrication of ordered ZnO nanowire arrays using Anodic Aluminium Oxide (AAO) template. We have used a vacuum injection technique to fill solution into the pores of an AAO template. The AAO template has been fabricated by a two-step anodization process using 0.3 M oxalic acid (H 2 C 2 O 4 ) solution under a constant voltage of 40 V. The AAO template formed through this process has been detached from Al substrate via an anodic voltage pulse using perchloric acid (HClO 4 ) solution (70%). The nanowires of ZnO have been synthesized by injecting the saturated Zn(NO 3 ) 2 solution into the pores of the detached AAO template using a vacuum pump. The ZnO nanowires synthesized by this technique have been found dense & continuous with uniform diameter throughout the length of the wire. The structural characteristics of AAO template and ZnO nanowires have been studied by Field Emission Scanning Electron Microscope (FESEM), Atomic force microscope (AFM) and Transmission Electron Microscope (TEM). Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6402-4 Authors Nagesh Kumar, Department of Physics and Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667 India G. D. Varma, Department of Physics and Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667 India R. Nath, Department of Physics and Centre of Nanotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667 India A. K. Srivastava, Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore, 452013 India Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The electrical characteristics of thin TiO 2 films prepared by metal–organic chemical vapor deposition grown on a p-type InP substrate were studied. For a TiO 2 film of 4.7 nm on InP without and with ammonium sulfide treatment, the leakage currents are 8.8×10 −2 and 1.1×10 −4  A/cm 2 at +2 V bias and 1.6×10 −1 and 8.3×10 −4  A/cm 2 at −2 V bias. The lower leakage currents of TiO 2 with ammonium sulfide treatment arise from the improvement of interface quality. The dielectric constant and effective oxide charge number density are 33 and 2.5×10 13  cm 2 , respectively. The lowest mid-gap interface state density is around 7.6×10 11  cm −2  eV −1 . The equivalent oxide thickness is 0.52 nm. The breakdown electric field increases with decreasing thickness in the range of 2.5 to 7.6 nm and reaches 9.3 MV/cm at 2.5 nm. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6404-2 Authors Ming-Kwei Lee, Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung, 80424 Taiwan, R.O.C. Chih-Feng Yen, Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung, 80424 Taiwan, R.O.C. Shih-Chen Chiu, Department of Electrical Engineering, National Sun Yat-sen University, Kaohsiung, 80424 Taiwan, R.O.C. Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Electrical transport properties on polycrystalline Cu(In,Ga)Se 2 (CIGS) (Ga/(In+Ga) ≈35%) thin films were examined by conductive atomic force microscopy. The CIGS thin films with a (112) preferential or random texture were deposited on Mo-coated glass substrates. Triangular pyramidal grain growths were observed in the CIGS thin films preferentially textured to the (112) planes. Current maps of the CIGS surface were acquired with a zero or non-zero external voltage bias. The contrast of the images on the grain boundaries and intragrains displayed the conduction path in the materials. Local current–voltage measurements were performed to evaluate the charge conduction properties of the CIGS thin films. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6408-y Authors R. H. Shin, Department of Physics, Ewha Womans University, Seoul, 120-750 Korea W. Jo, Department of Physics, Ewha Womans University, Seoul, 120-750 Korea D.-W. Kim, Department of Physics, Ewha Womans University, Seoul, 120-750 Korea Jae Ho Yun, Korea Institute of Energy Research, Daejeon, 305-343 Korea S. Ahn, Korea Institute of Energy Research, Daejeon, 305-343 Korea Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We consider a four-layer waveguide structure as an optical waveguide sensor. One of the layers is a metamaterial with negative permittivity and permeability. We show that the sensitivity of the proposed optical waveguide sensor can be dramatically enhanced by using a metamaterial layer between the guiding and the cladding layers. The variation of the sensitivity of the proposed waveguide sensor with different parameters of the waveguide is studied. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6406-0 Authors Sofyan A. Taya, Physics Department, Islamic University, P.O. Box 108, Gaza Strip, Gaza, Palestine Mohammed M. Shabat, Physics Department, Islamic University, P.O. Box 108, Gaza Strip, Gaza, Palestine Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Following studies of biological attachment systems, the principle of contact splitting, according to which splitting up the contact into finer subcontacts increases adhesion, was introduced. However, numerous attempts at employing this principle in producing dry adhesives were unsuccessful, prompting us to test its validity. Here, we show that in addition to the increase in number of subcontacts, the contact splitting model also implies a built-in increase in contact area. Thus, based on this model, it is impossible to say which parameter leads to increase in adhesion, the increasing number of subcontacts, as accepted to think, or just an increase in contact area, which is a trivial result. To clarify this point, we show experimentally what happens if we keep the contact area constant, while increasing the number of subcontacts in the “equal load sharing” mode, which was never done before. In contrast to the contact splitting principle, our measurements clearly demonstrate that, in flat-punch-patterned conformal contact, the pull-off force remains the same even when the number of subcontacts increases by two orders of magnitude. Our finding suggests that the contact splitting idea can only work in thin-film-based contacts, which are indeed employed in most biological temporary attachment systems. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6394-0 Authors Michael Varenberg, Department of Mechanical Engineering, Technion-IIT, Haifa, 32000 Israel Boris Murarash, Department of Mechanical Engineering, Technion-IIT, Haifa, 32000 Israel Yuri Kligerman, Department of Mechanical Engineering, Technion-IIT, Haifa, 32000 Israel Stanislav N. Gorb, Department of Functional Morphology and Biomechanics, Zoological Institute of the University of Kiel, Kiel, 24098 Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Single-crystalline ZnO nanowires on a sapphire substrate have been synthesized by a nanoparticle-assisted pulsed-laser deposition (NAPLD) using a pure and Sb 2 O 3 doped ZnO target. Low density and vertically well-aligned ZnO nanowires were grown on hexagonal cone-shape ZnO cores by introduction of a ZnO buffer layer. More than 90% of the ZnO cores of the Sb-induced ZnO nanowires are formed in the same size of 400 nm. The ZnO nanowires consist of single-crystalline wurtzite ZnO crystal and grow along [0001] direction. The room-temperature photoluminescence spectrum exhibited a strong ultraviolet emission at around 380 nm and a relatively low broad band emission in the visible region, indicating a low concentration of structural defect in the nanowires. Sb can be used as one of the effective additives to control the morphology and alignment of ZnO nanowires synthesized by NAPLD. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6401-5 Authors D. Nakamura, Department of Electrical Engineering, Graduate School of Information and Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan K. Okazaki, Department of Electrical Engineering, Graduate School of Information and Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan I. A. Palani, Department of Electrical Engineering, Graduate School of Information and Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan M. Higashihata, Department of Electrical Engineering, Graduate School of Information and Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan T. Okada, Department of Electrical Engineering, Graduate School of Information and Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395 Japan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We report on recent insights into the interaction between ultra-fast laser pulses and plasmonic nanoparticles. We discuss femtosecond near-field ablation as a simple but versatile tool for the nanoscale modification of surfaces and the high-resolution measurement of a nanostructure’s near field. Two model systems are presented, illustrating the complexity of near-field distributions. Furthermore, finite difference time domain calculations in combination with absorption spectra provide a deeper insight into the factors influencing the near-field distribution. For the first time, an almost perfect agreement between the measured ablation pattern and experiment has been reached for gold triangles with a side length around 500 nm. Additionally, the results from picosecond laser irradiated plasmonic structures display a new regime of nanoscale laser material processing. We present first results showing nanometre confined melting induced by laser pulses. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6443-8 Authors A. Kolloch, University of Konstanz, Konstanz, Germany T. Geldhauser, Research Institute of Electronic Science, Hokkaido University, Sapporo, Japan K. Ueno, Research Institute of Electronic Science, Hokkaido University, Sapporo, Japan H. Misawa, Research Institute of Electronic Science, Hokkaido University, Sapporo, Japan J. Boneberg, University of Konstanz, Konstanz, Germany A. Plech, Karlsruhe Institut für Technologie, Karlsruhe, Germany P. Leiderer, University of Konstanz, Konstanz, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Silver-doped silicon thin films were deposited on glass substrate in a co-sputtering procedure. Silver nanoparticles were segregatedly distributed. The nonlinear properties were extracted by z -scan measurements at low laser input power. For about 50% silver density, the nonlinear absorption and refraction coefficients peaked, respectively, at −8.086×10 −2  m/W and 1.47×10 −9  m 2 /W, which, with respect to the input intensity, are several orders higher than reported data. The sudden surge of nonlinear responses was explained satisfactorily based on a self-consistent microscopic model calculation for silver clusters. Resonances exist and depend apparently on the laser-modified local cluster concentration. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6464-3 Authors Jingsong Wei, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800 China Jing Liu, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800 China Mufei Xiao, Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apartado Postal 365, CP 22800 Ensenada, Baja California, Mexico Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We fabricated and measured the far-field optical properties of a sub-wavelength Si 3 N 4 (silicon nitride) two dimensional grating. Frequency-dependent transmission measurements from a white-light source revealed that both transverse magnetic (TM) and transverse electric (TE) modes were excited on the grating. We determined the dispersion relations of the modes by tilting the sample with respect to the incoming light beam and measuring the frequency shift of the absorption features. By comparing to a simple model, we determined the effective refractive index for the TM and TE modes and the geometrical constants for the grating. This information enables gratings with desired optical properties to be designed and fabricated. The application of the sub-wavelength grating for surface-enhanced Raman scattering (SERS) is demonstrated. Content Type Journal Article Category Invited paper Pages 1-6 DOI 10.1007/s00339-011-6613-8 Authors Min Hu, Hewlett Packard Laboratories, 1501 Page Mill Road, Palo Alto, CA 94304, USA David Fattal, Hewlett Packard Laboratories, 1501 Page Mill Road, Palo Alto, CA 94304, USA Jingjing Li, Hewlett Packard Laboratories, 1501 Page Mill Road, Palo Alto, CA 94304, USA Xuema Li, Hewlett Packard Laboratories, 1501 Page Mill Road, Palo Alto, CA 94304, USA Zhiyong Li, Hewlett Packard Laboratories, 1501 Page Mill Road, Palo Alto, CA 94304, USA R. Stanley Williams, Hewlett Packard Laboratories, 1501 Page Mill Road, Palo Alto, CA 94304, USA Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Matrix-assisted pulsed laser evaporation (MAPLE) is a prominent member of a broad and expanding class of laser-driven deposition techniques where a matrix of volatile molecules absorbs laser irradiation and provides the driving force for the ejection and transport of the material to be deposited. The mechanisms of MAPLE are investigated in coarse-grained molecular dynamic simulations focused on establishing the physical regimes and limits of the molecular transfer from targets with different structures and compositions. The systems considered in the simulations include dilute solutions of polymer molecules and individual carbon nanotubes (CNTs), as well as continuous networks of carbon nanotubes impregnated with solvent. The polymer molecules and nanotubes are found to be ejected only in the ablation regime and are incorporated into matrix-polymer droplets generated in the process of the explosive disintegration of the overheated matrix. The ejection and deposition of droplets explain the experimental observations of complex surface morphologies in films deposited by MAPLE. In simulations performed for MAPLE targets loaded with CNTs, the ejection of individual nanotubes, CNT bundles, and tangles with sizes comparable or even exceeding the laser penetration depth is observed. The ejected CNTs align along the flow direction in the matrix plume and tend to agglomerate into bundles at the initial stage of the ablation plume expansion. In a large-scale simulation performed for a target containing a network of interconnected CNT bundles, a large tangle of CNT bundles with the total mass of 50 MDa is separated from the continuous network and entrained with the matrix plume. No significant splitting and thinning of CNT bundles in the ejection process is observed in the simulations, suggesting that fragile structural elements or molecular agglomerates with complex secondary structures may be transferred and deposited to the substrate with the MAPLE technique. Content Type Journal Article Pages 1-18 DOI 10.1007/s00339-011-6595-6 Authors Leonid V. Zhigilei, Department of Materials Science and Engineering, University of Virginia, 395 McCormick Road, Charlottesville, VA 22904-4745, USA Alexey N. Volkov, Department of Materials Science and Engineering, University of Virginia, 395 McCormick Road, Charlottesville, VA 22904-4745, USA Elodie Leveugle, Department of Materials Science and Engineering, University of Virginia, 395 McCormick Road, Charlottesville, VA 22904-4745, USA Marshall Tabetah, Department of Materials Science and Engineering, University of Virginia, 395 McCormick Road, Charlottesville, VA 22904-4745, USA Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Effects of a mechanical shear on the electron transport properties of a (LaMnO 3 ) 2 /(SrMnO 3 ) 2 superlattice are investigated using first-principle DFT calculations. While the unstrained superlattice is a 3-D conducting half metal, application of a pyramidal shear transforms it into a non-spin-polarized conductor. Depending on whether the out-of-plane component of the shear is tensile or compressive the conductivity is 1-D out-of-plane or 2-D in-plane. The shear-induced low-dimensional conductivity is also associated with the FM-AFM transition. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6607-6 Authors Dan Cao, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China Yue Zheng, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China C. H. Woo, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hong Kong, Hong Kong SAR, China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    This review discusses the origins and evolution of the MAPLE technique as it started as an alternative to spray coating of thin films for chemical vapor sensors. It describes its numerous applications for the deposition of thin films of polymeric, organic and biomaterials for various applications. This is followed by an overview of several new variations of the MAPLE technique. This review concludes with an outlook on the future of this highly versatile and successful vapor deposition process. Content Type Journal Article Pages 1-12 DOI 10.1007/s00339-011-6594-7 Authors Alberto Piqué, Materials Science and Technology Division, Naval Research Laboratory, Washington, DC, USA Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The demand for micromachining of coronary stents by means of industrial lasers rises quickly for treating coronary artery diseases, which cause more than one million deaths each year. The most widely used types of laser for stent manufacturing are Nd:YAG laser systems with a wavelength of 1064 nm with pulse lengths of 10 −3 –10 −2  seconds. Considerable post-processing is required to remove heat-affected zones (HAZ), and to improve surface finishes and geometry. Using a third harmonic laser radiation of picosecond laser (6×10 −12  s pulse duration) in UV range, the capability of the picosecond laser micromachining of nitinol and platinum–iridium alloy for coronary stent applications are presented. In this study dross-free cut of nitinol and platinum–iridium alloy tubes are demonstrated and topography analysis of the cut surface is carried out. The HAZ characteristics have been investigated by means of microscopic examinations and measurement of micro-hardness distribution near the cut zones. Content Type Journal Article Pages 1-11 DOI 10.1007/s00339-011-6609-4 Authors N. Muhammad, Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL Manchester, UK D. Whitehead, Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL Manchester, UK A. Boor, Swiss Tec AG, Bahnhofstrasse 7, 9494 Schaan, Principality of Liechtenstein W. Oppenlander, Swiss Tec AG, Bahnhofstrasse 7, 9494 Schaan, Principality of Liechtenstein Z. Liu, Corrosion and Protection Centre, School of Materials, The University of Manchester, M13 9PL Manchester, UK L. Li, Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL Manchester, UK Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We studied single-crystal copper of three different crystallographic orientations [(100), (011) and (111)] for nanoindentation response via a numerical simulation model using spherical indenters of radius (R) 3.4 μm and 10 μm. The model uses rate-independent crystal plasticity with a finite strain implemented as a user routine in the commercial finite element software ABAQUS. The model takes into account active crystallographic slip, orientation effects during nanoindentation computation, and the effect of friction between the indenter and copper substrate. We compared the load–displacement curve and indentation pile-up patterns obtained from the simulations with experimental measurements available in the literature. The indentation load and mean effective pressure beneath the indenter p m were found to be highest for (111) orientation and lowest for (100). The simulation and experimental data agree well. Content Type Journal Article Pages 1-9 DOI 10.1007/s00339-011-6618-3 Authors Karthic R. Narayanan, School of Mechanical & Aerospace Engineering, Nanyang Technological University, Singapore, 639798 Singapore S. Subbiah, School of Mechanical & Aerospace Engineering, Nanyang Technological University, Singapore, 639798 Singapore I. Sridhar, School of Mechanical & Aerospace Engineering, Nanyang Technological University, Singapore, 639798 Singapore Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The structural and optical properties of the needle-like ZnO nanostructure grown on the carbon nanotubes (ZnO/CNTs) have been studied by scanning electron microscope (SEM), X-ray diffraction (XRD), and photoluminescence (PL) spectra. It can be seen that there is about tens of nanometers in diameter of the single ZnO nanorod from the SEM picture. The XRD analysis shows that the prepared film is of typical wurtzite hexagonal phase without impurity. Temperature dependence of electronic transitions in the ZnO/CNTs has been investigated by PL in detail. The emission features in near band gap at 10 K reveal a redshift trend compared to ZnO single crystal, which is associated with the strong interfacial connection between ZnO and CNTs. Moreover, the intensities of all transitions in near band gap and visible regions decrease with increasing the temperature but increase with the excitation power. It can be concluded that the combined effect from ZnO and CNTs plays an important role in the PL response. The emission variations with the temperature for the ZnO/CNTs are the result of the electron–phonon interaction and the lattice thermal expansion. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6622-7 Authors Deyan Peng, Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241 People’s Republic of China Xiangui Chen, Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241 People’s Republic of China Yang Wang, Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241 People’s Republic of China Zhigao Hu, Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241 People’s Republic of China Ke Yu, Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241 People’s Republic of China Ziqiang Zhu, Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai, 200241 People’s Republic of China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Inductively coupled plasma (ICP) etching of GaN is systemically investigated by changing ICP power/RF bias power, operating pressure, and Cl 2 /BCl 3 gas mixing ratio. The hexagonal etch pits related to screw dislocation existing along GaN epitaxial layer were observed on the etched GaN surface after ICP etching. The intensity of band-edge emission is significantly reduced from the etched n-GaN surface, which reveals that plasma-induced damage are generated after ICP etching. The oblique sidewall is transferred into GaN using a combination of Cl 2 /BCl 3 plasma chemistry and hard mask SiO 2 . By adjusting ICP etching process parameters, oblique sidewalls with various oblique angles can be formed, allowing for conformal metal lines coverage across the mesa structures, which can play an important role in the interconnection of multiple microchips for light emitting diodes (LEDs) fabrication. Content Type Journal Article Pages 1-9 DOI 10.1007/s00339-011-6508-8 Authors Shengjun Zhou, Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai, 200240 China Bin Cao, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science & Technology, Wuhan, 430074 China Sheng Liu, Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai, 200240 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In this paper, we have studied field emission properties of highly dense arrays of multi-walled carbon nanotubes (CNTs) used as cathodes in diode-type field emission devices with a phosphor screen. For the high-density CNT emitters it is demonstrated that the emission sites are located on the CNT-cathode edges, which is direct experimental evidence of the ‘edge effect’. The results of computer simulations (using ‘ANSYS Electromagnetic’ software) are presented to confirm the experimental data and to analyze the effect of patterning on the electric field distribution for high-density CNT arrays. It is shown that selective-area removal of nanotubes in the arrays leads to the formation of additional edges characterized by the high field enhancement factor and enhanced emission from the CNT cathodes. In addition, scanning probe microscopy techniques are employed to examine surface properties of the high-density CNT arrays. For CNT arrays of ‘short’ nanotubes, the work function distribution over the sample surface is detected using a scanning Kelvin microscopy method. Content Type Journal Article Category Rapid communication Pages 1-6 DOI 10.1007/s00339-011-6584-9 Authors Sergei M. Pimenov, Natural Sciences Center, General Physics Institute, Moscow, 119991 Russia Vadim D. Frolov, Natural Sciences Center, General Physics Institute, Moscow, 119991 Russia Evgeny V. Zavedeev, Natural Sciences Center, General Physics Institute, Moscow, 119991 Russia Nikolay P. Abanshin, R&D Institute ‘Volga’, Saratov, 410052 Russia He-Yun Du, Institute of Atomic and Molecular Science, Academia Sinica, Taipei, 106 Taiwan Wei-Chao Chen, Institute of Atomic and Molecular Science, Academia Sinica, Taipei, 106 Taiwan Li-Chyong Chen, Center for Condensed Matter Sciences, National Taiwan University, Taipei, 106 Taiwan Jih-Jen Wu, Department of Chemical Engineering, National Cheng Kung University, Tainan, 701 Taiwan Kuei-Hsien Chen, Institute of Atomic and Molecular Science, Academia Sinica, Taipei, 106 Taiwan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Iron-doped X-cut lithium niobate crystals were prepared by means of thermal diffusion from thin film varying in a systematic way the process parameters such as temperature and diffusion duration. Secondary Ion Mass Spectrometry was exploited to characterize the iron in-depth profiles. The evolution of the composition of the Fe thin film in the range between 600°C and 800°C was studied, and the diffusion coefficient at different temperatures in the range between 900°C and 1050°C and the activation energy of the diffusion process were estimated. Content Type Journal Article Pages 1-8 DOI 10.1007/s00339-011-6559-x Authors M. V. Ciampolillo, Physics Department and CNISM, University of Padova, Padova, Italy N. Argiolas, Physics Department and CNISM, University of Padova, Padova, Italy A. Zaltron, Physics Department and CNISM, University of Padova, Padova, Italy M. Bazzan, Physics Department and CNISM, University of Padova, Padova, Italy C. Sada, Physics Department and CNISM, University of Padova, Padova, Italy Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Spectroscopic methods using laser sources have significantly improved our capacity to unravel the chemical composition of works of art and archaeological remains. Lasers enhance the performance of spectroscopic techniques which require intense light sources and specific analytical protocols assuring a microanalytical approach for analysis has been established. This review focuses on laser spectroscopic methods used in the field of cultural heritage diagnostics. Emphasis in this work is given to the analytical capabilities of laser-based techniques for elemental and/or molecular analysis and in-situ use, spatial resolution and microanalysis. Analytical methods are classified according to the elemental (LIBS, LA–ICP–MS) and molecular (LIF/LIDAR, time-resolved absorption spectroscopy, laser desorption ionization mass spectrometry) information they yield. For non-destructive laser-induced fluorescence (LIF/LIDAR) and time-resolved fluorescence spectroscopy, imaging applications are described. The advantages provided by combined complementary techniques including but not limited to LIBS–LIF–Raman and LIBS–XRF are presented, as are recent improvements in terms of chemical imaging. Advances and applications of THz spectroscopy, non-linear spectroscopy and imaging are outlined. Finally, laser spectroscopies are described for investigations of different materials and works of art which include Bronze Age ceramics, Minoan archaeological remains, Ancient Roman buildings, Renaissance wall paintings and sculptures, and manuscripts containing iron gall inks and colorants. Content Type Journal Article Category Invited paper Pages 1-23 DOI 10.1007/s00339-011-6699-z Authors Austin Nevin, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy Giuseppe Spoto, Dipartimento di Scienze Chimiche, Università di Catania, Viale A. Doria 6, 95125 Catania, Italy Demetrios Anglos, Institute of Electronic Structure and Laser, Foundation for Research and Technology–Hellas, P.O. Box 1385, 71110 Heraklion, Crete, Greece Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We present the results of the characterization of Mg/Co periodic multilayers and their thermal stability for the EUV range. The annealing study is performed up to a temperature of 400 ∘ C. Images obtained by scanning transmission electron microscopy and electron energy loss spectroscopy clearly show a good quality of the multilayer structure. The measurements of the EUV reflectivity around 25 nm (∼49 eV) indicate that the reflectivity decreases when the annealing temperature increases above 300 ∘ C. X-ray emission spectroscopy is performed to determine the chemical state of the Mg atoms within the Mg/Co multilayer. Nuclear magnetic resonance used to determine the chemical state of the Co atoms and scanning electron microscopy images of cross sections of the Mg/Co multilayers reveal changes in the morphology of the stack from an annealing temperature of 305 ∘ C. This explains the observed reflectivity loss. Content Type Journal Article Pages 1-9 DOI 10.1007/s00339-011-6681-9 Authors M.-H. Hu, Laboratoire Chimie Physique—Matière Rayonnement, UPMC Univ Paris 06, CNRS UMR 7614, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France K. Le Guen, Laboratoire Chimie Physique—Matière Rayonnement, UPMC Univ Paris 06, CNRS UMR 7614, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France J.-M. André, Laboratoire Chimie Physique—Matière Rayonnement, UPMC Univ Paris 06, CNRS UMR 7614, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France S. K. Zhou, Institute of Precision Optical Engineering, Department of Physics, Tongji University, Shanghai, 200092 P.R. China H. C. Li, Institute of Precision Optical Engineering, Department of Physics, Tongji University, Shanghai, 200092 P.R. China J. T. Zhu, Institute of Precision Optical Engineering, Department of Physics, Tongji University, Shanghai, 200092 P.R. China Z. S. Wang, Institute of Precision Optical Engineering, Department of Physics, Tongji University, Shanghai, 200092 P.R. China C. Meny, Institut de Physique et Chimie des Matériaux de Strasbourg, CNRS UMR 7504, 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2, France N. Mahne, CNR-IOM Laboratorio TASC, SS 14 km 163,5, 34149 Basovizza, Trieste, Italy A. Giglia, CNR-IOM Laboratorio TASC, SS 14 km 163,5, 34149 Basovizza, Trieste, Italy S. Nannarone, CNR-IOM Laboratorio TASC, SS 14 km 163,5, 34149 Basovizza, Trieste, Italy I. Estève, Institut de Minéralogie et de Physique des Milieux Condensés, Univ Paris 06 et 07, CNRS UMR 7590, 4 place Jussieu, 75252 Paris Cedex 05, France M. Walls, Laboratoire de Physiques des Solides, CNRS UMR 8502, Univ Paris Sud, 91405 Orsay, France P. Jonnard, Laboratoire Chimie Physique—Matière Rayonnement, UPMC Univ Paris 06, CNRS UMR 7614, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Mesoporous poly (acrylic acid)/SiO 2 (PAA/SiO 2 ) composite nanofiber membranes functionalized with mercapto groups were fabricated by a sol-gel electrospinning method, and their adsorption capacity for indigo carmine was investigated. The membranes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, x-ray powder diffraction (XRD), and nitrogen adsorption–desorption measurement. SEM and TEM observation results showed that the PAA/SiO 2 fibers had diameters between 400–800 nm and mesopores with an average pore size of 3.88 nm. The specific surface area of the mesoporous nanofiber membranes was 514.89 m 2 /g. The characteristic peaks for mercapto group vibration in FTIR and Raman spectra demonstrated that the mercapto groups have been incorporated into the silica skeleton. The adsorption isotherm data of indigo carmine on the membranes fit well with Redlich–Peterson model, and the maximum adsorption capacity calculated was 523.11 mg/g. It was found that the removal rate of indigo carmine by the membranes reached a maximum of 98% in 90 min and the adsorption kinetics followed a pseudo-second-order model. The high adsorption capacity of PAA/SiO 2 nanofiber membrane makes it a promising adsorbent for indigo carmine removal from the wastewater. Content Type Journal Article Pages 1-9 DOI 10.1007/s00339-011-6697-1 Authors Ran Xu, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai, 200092 P.R. China Min Jia, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai, 200092 P.R. China Fengting Li, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai, 200092 P.R. China Hongtao Wang, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai, 200092 P.R. China Bingru Zhang, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai, 200092 P.R. China Junlian Qiao, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai, 200092 P.R. China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We report on the fabrication of three dimensional micro-fluidic channels in fused silica glass using a combination of femtosecond laser writing and hydrofluoric acid wet etching to flexibly create various cross-sectional profiles of highly uniform shape and smooth vertical walls. The laser power, polarization, focusing depth, scanning angle and scanning speed were systematically studied with single- and multi-scan configurations to assess optimum micro-channel formation including etch rate, surface roughness, and stress-induced crack formation. We introduce the formation of vertical access-ports that extend the buried channel formation to unlimited length without tapering or distortion of the channel cross-sectional shape. Content Type Journal Article Category Invited paper Pages 1-9 DOI 10.1007/s00339-011-6675-7 Authors Stephen Ho, The Edward S. Rogers Sr. Department of Electrical and Computer Engineering and the Institute for Optical Sciences, University of Toronto, 10 King’s College Road, Toronto, M5S 3G4 Ontario, Canada Peter R. Herman, The Edward S. Rogers Sr. Department of Electrical and Computer Engineering and the Institute for Optical Sciences, University of Toronto, 10 King’s College Road, Toronto, M5S 3G4 Ontario, Canada J. Stewart Aitchison, The Edward S. Rogers Sr. Department of Electrical and Computer Engineering and the Institute for Optical Sciences, University of Toronto, 10 King’s College Road, Toronto, M5S 3G4 Ontario, Canada Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The paper is directed to all classes of optical inspection technologies that are causing a fringe pattern like output, such as interferometry, fringe projection, holography, speckle techniques. The explanations given here are also valid for incoherent fringe projection, moire, and short-coherent techniques, which are producing fringe-like output correlated with the surface structure and the surface change, respectively. Identification of interference fringe patterns with defect type is a long-standing engineering problem with the ambiguities in cause-effect relation dominating the Cultural Heritage structural diagnosis. The ambiguities refer to fringe-pattern formation in regard to a hidden defect cause in the subsurface and the effect on the surface of the size or depth of the defect. In order to solve the concerned ambiguities, a review is made here to be confirmed a correlation of fringe pattern appearance to defect cause. The methodology is employed in the paper to achieve a generalized description of fringe morphology for a common type of inner defect as interlayer de-cohesion termed in art conservation as detachment and crack. The objective is to provide the required concept and procedure through which the validation of any defect-indicative fringe-pattern can serve as a direct-visual-control of structural condition in artwork examination. In this context, theoretical and experimental results starting from simulation algorithms, through knowledge based experiments and experimental verification to correlation procedures and mathematical analysis are combined to allow fringe pattern generalized validation. The result allows performing by means of modern optical metrology direct artwork documentation of structural diagnosis in complex art conservation problems. It helps to utilize it in other research objectives targeting in automated defect-recognition and multisensory technology. It helps to advance theoretical and practical routines in everyday practices of art conservation applications, to confirm the direct fringe pattern concept in a new diagnostic field, and develop associations to cause-effect relations in other art conservation problems. Content Type Journal Article Category Invited paper Pages 1-14 DOI 10.1007/s00339-011-6695-3 Authors Vivi Tornari, Foundation for Research and Technology-Hellas, Institute of Electronic Structure and Laser Vassilika Vouton, Voutes, 71 110 Heraklion, Crete, Greece Elsa Tsiranidou, Foundation for Research and Technology-Hellas, Institute of Electronic Structure and Laser Vassilika Vouton, Voutes, 71 110 Heraklion, Crete, Greece Eirini Bernikola, Foundation for Research and Technology-Hellas, Institute of Electronic Structure and Laser Vassilika Vouton, Voutes, 71 110 Heraklion, Crete, Greece Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We investigated the twin domain distribution and lattice parameter variations associated with the displacive phase transition in SrTiO 3 by means of X-ray diffraction with high spatial resolution. By using 4.5-keV photons, the probed region is the first micrometer near the surface. We find a very inhomogeneous domain distribution, showing both regions with large monodomains and highly twinned regions, as well as large needle domains. Also, the lattice parameters in these different regions vary substantially. Content Type Journal Article Pages 1-4 DOI 10.1007/s00339-011-6674-8 Authors Robert Loetzsch, Helmholtz Institut Jena, Helmholtzweg 4, 07743 Jena, Germany Ingo Uschmann, Helmholtz Institut Jena, Helmholtzweg 4, 07743 Jena, Germany Eckhard Förster, Helmholtz Institut Jena, Helmholtzweg 4, 07743 Jena, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Quantitative X-ray fluorescence (XRF) and particle induced X-ray emission (PIXE) techniques have been developed mostly for the elemental analysis of homogeneous bulk or very simple layered materials. Further on, the microprobe version of both techniques is applied for 2D elemental mapping of surface heterogeneities. At typical XRF/PIXE fixed geometries and exciting energies (15–25 keV and 2–3 MeV, respectively), the analytical signal (characteristic X-ray radiation) emanates from a variable but rather extended depth within the analyzed material, according to the exciting probe energy, set-up geometry, specimen matrix composition and analyte. Consequently, the in-depth resolution offered by XRF and PIXE techniques is rather limited for the characterization of materials with micrometer-scale stratigraphy or 3D heterogeneous structures. This difficulty has been over-passed to some extent in the case of an X-ray or charged particle microprobe by creating the so-called confocal geometry. The field of view of the X-ray spectrometer is spatially restricted by a polycapillary X-ray lens within a sensitive microvolume formed by the two inter-sectioned focal regions. The precise scanning of the analyzed specimen through the confocal microvolume results in depth-sensitive measurements, whereas the additional 2D scanning microprobe possibilities render to element-specific 3D spatial resolution (3D micro-XRF and 3D micro-PIXE). These developments have contributed since 2003 to a variety of fields of applications in environmental, material and life sciences. In contrast to other elemental imaging methods, no size restriction of the objects investigated and the non-destructive character of analysis have been found indispensable for cultural heritage (CH) related applications. The review presents a summary of the experimental set-up developments at synchrotron radiation beamlines, particle accelerators and desktop spectrometers that have driven methodological developments and applications of confocal X-ray microscopy including depth profiling speciation studies by means of confocal X-ray absorption near edge structure (XANES) spectroscopy. The solid mathematical formulation developed for the quantitative in-depth elemental analysis of stratified materials is exemplified and depth profile reconstruction techniques are discussed. Selected CH applications related to the characterization of painted layers from paintings and decorated artifacts (enamels, glasses and ceramics), but also from the study of corrosion and patina layers in glass and metals, respectively, are presented. The analytical capabilities, limitations and future perspectives of the two variants of the confocal micro X-ray spectroscopy, 3D micro-XRF and 3D micro-PIXE, with respect to CH applications are critically assessed and discussed. Content Type Journal Article Category Invited paper Pages 1-14 DOI 10.1007/s00339-011-6698-0 Authors B. Kanngießer, Institut für Optik und Atomare Physik, Technical University of Berlin, Sekr. EW 3-2, Raum 346, Hardenbergstr. 36, 10623 Berlin, Germany W. Malzer, Institut für Optik und Atomare Physik, Technical University of Berlin, Sekr. EW 3-2, Raum 346, Hardenbergstr. 36, 10623 Berlin, Germany I. Mantouvalou, Institut für Optik und Atomare Physik, Technical University of Berlin, Sekr. EW 3-2, Raum 346, Hardenbergstr. 36, 10623 Berlin, Germany D. Sokaras, Institute of Nuclear Physics, NCSR ‘Demokritos’, 153 10 Athens, Greece A. G. Karydas, Institute of Nuclear Physics, NCSR ‘Demokritos’, 153 10 Athens, Greece Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The electroplex between (2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazole) zinc [Zn(4-TfmBTZ) 2 ] as an electron-acceptor and N,N′-diphenyl-N,N′-bis(1-naphthyl)-(1,1′-biphenyl)-4,4′-diamine (NPB) as an electron-donor was characterized by bilayer, blend, and multilayer quantum-well (MQW) device, respectively. The blend composition and quantum-well number are effective parameters for tuning electroluminescence color. White light with high color purity and color rendering index (CRI) was observed from these devices based on Zn(4-TfmBTZ) 2 /NPB. Moreover, the blend and MQW devices all exhibit high operation stability, hence excellent color stability. For the device with 5 mol% NPB in blend layer, its Commission International Del’Eclairage (CIE) coordinate region is x =0.28–0.31, y =0.33–0.35 and CRI is 83.3–91.2 at 5–9 V. For MQW structure device with NPB of 60 nm thickness, its CIE coordinate region is x =0.29–0.32, y =0.31–0.34 and CRI=87.9–92.5 at 10–15 V. Such high color stability and purity and CRI, being close to ideal white light, are of current important for white OLED. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6677-5 Authors Ye Zhang, College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan, 030024 China Yuying Hao, College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan, 030024 China Weixin Meng, College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan, 030024 China Huixia Xu, Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan, 030024 China Hua Wang, Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan, 030024 China Bingshe Xu, Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan, 030024 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In the last years, laser beam drilling became increasingly important for many technical applications as it allows the contactless production of high quality drill holes. So far, mainly short laser pulses are of industrial relevance, as they offer a good compromise between precision and efficiency and combine high ablation efficiency with low thermal damage of the workpiece. Laser beam drilling in this pulse length range is still a highly thermal process. There are two ablation mechanisms: evaporation and melt expulsion. In order to achieve high quality processing results, a basic process understanding is absolutely necessary. Yet, process observations in laser beam drilling suffer from both the short time scales and the restricted accessibility of the interaction zone. Numerical simulations offer the possibility to acquire additional knowledge of the process as they allow a direct look into the drill hole during the ablation process. In this contribution, a numerical finite volume multi-phase simulation model for laser beam drilling with short laser pulses shall be presented. The model is applied for a basic study of the ablation process with μs and ns laser pulses. The obtained results show good qualitative correspondence with experimental data. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6702-8 Authors Karl-Heinz Leitz, Chair of Photonic Technologies and Erlangen Graduate School in Advanced Optical Technologies (SAOT), University of Erlangen–Nuremberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany Holger Koch, Chair of Photonic Technologies and Erlangen Graduate School in Advanced Optical Technologies (SAOT), University of Erlangen–Nuremberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany Andreas Otto, Institute for Production Engineering and Laser Technology, Vienna University of Technology, Gusshausstrasse 30, 1040 Vienna, Austria Michael Schmidt, Chair of Photonic Technologies and Erlangen Graduate School in Advanced Optical Technologies (SAOT), University of Erlangen–Nuremberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In the last twenty years lasers have acquired an important role in the study and the preservation of Cultural Heritage (CH) objects and Monuments, as they have effectively illuminated a number of complex diagnostic and restoration problems. Their unique properties have enabled their use in a wide range of conservation applications, since they ensure interventions with precise control, material selectivity and immediate feedback. Surface cleaning, based on laser ablation, is a delicate, critical and irreversible process, which, given the multitude of materials that may be present on a CH object and the often fragile or precarious condition of the original surfaces, is fraught with many potential complications. Therefore it is crucial to choose the best possible laser cleaning methodology for each individual case, which involves optimising the laser parameters according to material properties, as well as the thorough knowledge of the ablation mechanisms involved. In this context the systematic investigation and elucidation of potential damage or side effects occurring upon cleaning is essential, as it delineates the possibilities and limitations of laser ablation and allows the fine-tuning of the operating parameters for a successful cleaning intervention. This paper is an overview of studies investigating the mechanisms which are responsible for the laser-induced discoloration effects. Emphasis is given on the yellowing coloration observed on stonework upon infrared (IR) ablation of pollution encrustations, while the various theories introduced to approach the different physical and/or chemical processes and mechanisms responsible for such side effects are discussed. In this respect the different laser cleaning methodologies, which are based on the use of laser systems with different pulse durations and wavelength characteristics, introduced in order to rectify or prevent discoloration on stonework are presented. In parallel, the darkening phenomena which occur upon laser irradiation of painted surfaces are also considered. Studies on series of model paints performed in order to understand the sensitivity of pigments to laser irradiation are critically reviewed. In this respect the importance of the optimal wavelength and pulse-duration selection for a safe and controlled laser cleaning intervention is also addressed. Content Type Journal Article Category Invited paper Pages 1-18 DOI 10.1007/s00339-011-6696-2 Authors Paraskevi Pouli, Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), P.O. Box 1385, 71110 Heraklion, Crete, Greece Mohamed Oujja, Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain Marta Castillejo, Instituto de Química Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Compared with the traditional split-ring resonator reported by Pendry et al. (IEEE Trans. Microw. Theory Tech. 47:2075, 1999 ), the co-directional split-ring resonator, which has inherent low mutual coupling between its outer and inner rings, can provide distinct dual-band magnetic resonances. In this paper, we analyzed and compared different types of split-ring resonator, but selected the co-directional split-ring resonator for the tri-band magnetic resonator design because of its attractive dual-band magnetic resonance characteristics. We then accommodated the rings’ resonant strengths in the co-directional split-ring resonator to be nearly equal, and added an arm-loaded ring to design a new tri-band magnetic resonator. Finally, we designed and experimentally demonstrated a broadband μ -negative planar material with low frequency dispersion, which consisted of three pairs of tri-band magnetic resonators with slightly different dimensions. Content Type Journal Article Pages 1-8 DOI 10.1007/s00339-011-6683-7 Authors Ming-Chun Tang, Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 People’s Republic of China Shaoqiu Xiao, Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 People’s Republic of China Tianwei Deng, School of Electrical and Electronic Engineering, Nanyang Technological University (NTU), Singapore, 639798 Singapore Yan Wang, Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 People’s Republic of China Yanying Bai, Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 People’s Republic of China Changrong Liu, Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 People’s Republic of China Yuping Shang, Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 People’s Republic of China Jiang Xiong, Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 People’s Republic of China Bingzhong Wang, Institute of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 People’s Republic of China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    A printed Z-shaped electric meta-atom is presented as an alternative design to the conventional electric-LC (ELC) resonator. We propose an easy way to redesign the ELC resonator pattern to get a compact and a low cost electric resonator exhibiting a strong electric response. Our approach involves, in the effective medium regime, redressing the resonator shape to accommodate higher inductance and lead to a lower resonance frequency without being limited by fabrication tolerances. The electromagnetic behaviour of the meta-atom has been investigated through both simulations and experiments in the microwave regime. Our results show that the Z meta-atom exhibits an electric response to normally incident radiation and can be used very effectively in producing materials with negative permittivity. The proposed planar meta-atom can find various applications in high frequency passive circuits which are designed in planar technology. Moreover, the proposed structure can be scaled to much higher frequencies via appropriate lithographic scaling. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6673-9 Authors Abdallah Dhouibi, LEME, Univ. Paris-Ouest, EA 4416, 92410 Ville d’Avray, France Shah Nawaz Burokur, LEME, Univ. Paris-Ouest, EA 4416, 92410 Ville d’Avray, France André de Lustrac, IEF, Univ. Paris-Sud, CNRS, UMR 8622, 91405 Orsay Cedex, France Alain Priou, LEME, Univ. Paris-Ouest, EA 4416, 92410 Ville d’Avray, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The positive temperature coefficient of resistance (PTCR) characteristics of Na 2 Ti 6 O 13 (NT)-doped 0.94BaTiO 3 –0.06(Bi 0.5 Na 0.5 )TiO 3 (BBNT) ceramics were investigated in order to evaluate the effect of NT as a new additive for lead-free PTCR thermistor application. The BBNT ceramic sintered at 1325°C exhibited a relatively high Curie temperature ( T C ) of 158°C while its PTCR characteristic was not satisfactory for thermistor application. However, doping with NT significantly influenced the PTCR behavior of BBNT ceramic. It is considered that NT was responsible for grain growth of the BBNT by forming a liquid phase during sintering due to its low melting temperature of 1300°C. The grain growth resulted in the enhanced PTCR characteristics of BBNT ceramic. In particular, 0.1 mol% NT doped BBNT ceramic exhibited excellent PTCR performance of low resistivity at room temperature (1.6×10 2  Ω cm), resistivity increase near T C (1.28×10 4 ) and high T C of 158°C, suitable for lead-free PTCR thermistor application. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6700-x Authors Young Hun Jeong, Optic and Electronic Ceramics Division, Korea Institute of Ceramic Engineering & Technology, 103 Fashion Danji-gil, Geumcheon-gu, Seoul, 153-801 Korea Yu-Joung Cha, Department of Materials Science and Engineering, Korea University, 5-1 Anam-Dong, Seungbuk-Gu, Seoul, 136-701 Korea Chang-Il Kim, Optic and Electronic Ceramics Division, Korea Institute of Ceramic Engineering & Technology, 103 Fashion Danji-gil, Geumcheon-gu, Seoul, 153-801 Korea Young-Jin Lee, Optic and Electronic Ceramics Division, Korea Institute of Ceramic Engineering & Technology, 103 Fashion Danji-gil, Geumcheon-gu, Seoul, 153-801 Korea Myoung-Pyo Jeon, Optic and Electronic Ceramics Division, Korea Institute of Ceramic Engineering & Technology, 103 Fashion Danji-gil, Geumcheon-gu, Seoul, 153-801 Korea Jeong-Ho Cho, Optic and Electronic Ceramics Division, Korea Institute of Ceramic Engineering & Technology, 103 Fashion Danji-gil, Geumcheon-gu, Seoul, 153-801 Korea Jong-Hoo Paik, Optic and Electronic Ceramics Division, Korea Institute of Ceramic Engineering & Technology, 103 Fashion Danji-gil, Geumcheon-gu, Seoul, 153-801 Korea Dae-Jun Kim, Hiel Corporation, 396-1 Haewol-Li, Soyang-Myeon, Wanju-Kun, Jeonbuk 565-840, Korea Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The transport of charges in organic photo-active film has been the focus of tremendous research in the past few decades with the view to understand the physics of the polymers. Bulk heterojunction type devices are particularly more interesting because of their high power conversion efficiency. We have fabricated organic PV cell based on sandwich type ITO/PEDOT:PSS/APFO green-6:PCBM/LiF/Al device structure. The space charge limited currents were investigated to be able to derive important transport parameters of the devices. The measured current agrees very well with trap free space charge limited transport theory. The zero field mobility and field activation factor found from the data were μ 0 =(3.39±0.2)×10 −6  m 2 /V sec and γ =(8.3±0.3)×10 −4  (m/V) 1/2 , respectively. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6676-6 Authors Genene Tessema, School of Physics, University of Kwazulu-Natal, Pietermaritzburg Campus, Private Bag X01, Scottsville, 3209 South Africa Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Double-pulse laser-induced breakdown spectroscopy (LIBS) is an emerging technique for accurate compositional analysis of many different materials. We present a systematic study of collinear double-pulse LIBS for analysis of the trace and side elements boron, manganese, copper, aluminum, titanium, silicon, chromium, nickel, potassium, and calcium in sintered iron oxide targets. The samples were ablated in air by single-pulse and double-pulse Nd:YAG laser radiation (6 ns pulse duration, laser wavelength of 532 nm) and spectra were recorded with an Echelle spectrometer equipped with an ICCD camera. We investigated the evolution of atomic and ionic line emission intensities for different interpulse delay times between the laser pulses (from 100 ns to 50 μs) and gate delays after the second laser pulse. We also varied the energy partition between the first and second laser pulse and the size of the irradiated spot at the sample surface. For the trace and side elements, we observed double-pulse LIBS signals that were enhanced as compared to single-pulse measurements depending on the interpulse delay time, the energy partition between the pulses, and the spot size. For the elements boron, copper, aluminum, titanium, chromium, potassium, and calcium limits of detection below 10 ppm were achieved. Content Type Journal Article Pages 1-9 DOI 10.1007/s00339-011-6669-5 Authors H. Heilbrunner, Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, 4040 Linz, Austria N. Huber, Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, 4040 Linz, Austria H. Wolfmeir, voestalpine Stahl GmbH, 4031 Linz, Austria E. Arenholz, voestalpine Stahl GmbH, 4031 Linz, Austria J. D. Pedarnig, Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, 4040 Linz, Austria J. Heitz, Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, 4040 Linz, Austria Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We investigate the frequency behavior of a half-wave dipole antenna placed very close over a 2LC uni-planar compact electromagnetic bandgap (UC-EBG) structure. A very compact and high-gain antenna is realized at 1 GHz. The air distance between the dipole element and the UC-EBG surface is ∼ λ 0 /100. We analyse the structure by using the optical model of Hansen, full-wave electromagnetic simulations (EM) and experimental characterizations. The analytical model of Hansen describes accurately the UC-EBG phase contribution to the total radiated field below 1 GHz. Above this frequency, the Hansen analytical model is in discrepancy with the measurements and full-wave simulations, which show split in the radiation patterns. We show that this phenomenon is induced by the power leakage of the fast-wave UC-EBG surface excited by the dipole source inside its leaky wave region. We propose an original model based on the Hansen optical analysis that takes into account the overall phenomena. The model includes the contribution of the weighted fields radiated by the cells of the UC-EBG. This model leads to very good agreements with measurements and full-wave simulations. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6656-x Authors Luyang Zhou, Laboratoire Energétique, Mécanique Electromagnétisme, LEME, Université Paris-Ouest Nanterre-La Défense, 50 rue de Sèvres, 92410 Ville d’Avray, France Habiba Hafdallah Ouslimani, Laboratoire Energétique, Mécanique Electromagnétisme, LEME, Université Paris-Ouest Nanterre-La Défense, 50 rue de Sèvres, 92410 Ville d’Avray, France Alain Priou, Laboratoire Energétique, Mécanique Electromagnétisme, LEME, Université Paris-Ouest Nanterre-La Défense, 50 rue de Sèvres, 92410 Ville d’Avray, France Abdelwahab Ourir, Institut Langevin, LOA-ESPCI, CNRS UMR 7587, 10 rue Vauquelin, 75005 Paris, France Olivier Maas, Division Air Systems Hameau de Roussigny, Thales Air Systems, 91470 Limours, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We obtain the repulsive Casimir force between two parallel gyroelectric slabs, thus overcoming the difficulty that the repulsive Casimir force is difficult to achieve in a naturally occurring material. Under practically realizable parameters, we realize the crossover from attractive (repulsive) to repulsive (attractive) forces by changing either the external static magnetic field, the background permittivity of the gyroelectric medium, the slab’s thickness or the gap between the slabs. The proposed configuration, unlike the artificial metamaterial one, does not require the careful design of the material’s micro-structure, and hence is expected to be a practical candidate for obtaining a repulsive Casimir force. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6684-6 Authors Guoding Xu, Department of Physics, Suzhou University of Science and Technology, Suzhou, 215009 P.R. China Jian Sun, Department of Physics, Suzhou University of Science and Technology, Suzhou, 215009 P.R. China Taocheng Zang, Department of Physics, Suzhou University of Science and Technology, Suzhou, 215009 P.R. China Hongmin Mao, Department of Physics, Suzhou University of Science and Technology, Suzhou, 215009 P.R. China Tao Pan, Department of Physics, Suzhou University of Science and Technology, Suzhou, 215009 P.R. China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In the present work the application of laser cleaning in the conservation of cultural assets is reviewed and some further developments on the interpretation of the associated laser-material interaction regimes are reported. Both the state of the art and new insights mainly focus on systematic approaches addressed to the solution of representative cleaning problems, including stone and metal artifacts along with wall and easel paintings. The innovative part is entirely dedicated to the extension of the application perspective of the Nd:YAG lasers by exploiting the significant versatility provided by their different pulse durations. Besides extensively discussing the specific conservation and physical problems involved in stone and metal cleaning, a significant effort was also made to explore the application potential for wall and easel paintings. The study of the latter was confined to preliminary irradiation tests carried out on prepared samples. We characterized the ablation phenomenology, optical properties, and photomechanical generation associated with the irradiation of optically absorbing varnishes using pulse durations of 10 and 120 ns. Further results concern the nature of the well-known problem of the yellowish appearance in stone cleaning, removal of biological growths and graffiti from stones, cleaning of bronze and iron artifacts and related aspects of laser conversion of unstable minerals, removal of calcareous stratification from wall paintings, and other features. Content Type Journal Article Category Invited paper Pages 1-28 DOI 10.1007/s00339-011-6690-8 Authors S. Siano, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, Firenze, Italy J. Agresti, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, Firenze, Italy I. Cacciari, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, Firenze, Italy D. Ciofini, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, Firenze, Italy M. Mascalchi, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, Firenze, Italy I. Osticioli, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, Firenze, Italy A. A. Mencaglia, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, Firenze, Italy Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The ferromagnetic transparent conducting film is a multifunctional film which has high visible transmittance, low resistivity and room-temperature ferromagnetism, simultaneously. In this article, ferromagnetic transparent conducting ZnO:Al/Fe 65 Co 35 /ZnO:Al multilayer films were fabricated by inserting a middle magnetic Fe 65 Co 35 layer into aluminum-doped zinc oxide (ZnO:Al) matrix using a magnetron sputtering apparatus at substrate temperature ranging from room temperature ( RT ) to 400 ∘ C. The total film thickness was about 400 nm and the middle Fe 65 Co 35 alloy layer was 4 nm. The influences of substrate temperature ( T s ) on the structural, electrical, optical and magnetic properties of the multilayer films were systemically investigated. The results showed that the microstructure and performance of the composite multilayer films strongly depended on the substrate temperature. The present results also showed that the inserted middle Fe 65 Co 35 alloy thin layer played an important role in providing the RT ferromagnetism and decreasing the resistivity of the multilayer films. Therefore, it is possible to obtain a multifunctional film material with the combination of good optical transparency, high electrical conductivity and RT ferromagnetism. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6679-3 Authors L. S. Wang, Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen, 361005 P.R. China S. J. Liu, College of Physics and Electric Information, Luoyang Normal University, Luoyang, 471022 P.R. China H. Z. Guo, Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen, 361005 P.R. China Y. Chen, Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen, 361005 P.R. China G. H. Yue, Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen, 361005 P.R. China D. L. Peng, Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen, 361005 P.R. China T. Hihara, Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya, 466-8555 Japan K. Sumiyama, Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya, 466-8555 Japan Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    X-ray fluorescence (XRF) spectroscopy and Raman spectroscopy are preferential analytical techniques to study cultural heritage objects, since both techniques may provide complementary information in a non-destructive manner. Moreover, the application of microscopic beams allows the investigation of heterogeneous samples on the microscopic level and the study of the heterogeneity of particular samples. The micro-XRF method became already a routine analytical imaging method also because of the well-established spectrum evaluation methodology enabling specific data handling procedures. These include multivariate statistical analysis procedures such as principal components analysis (PCA) in order to explore and describe the acquired data, and clustering techniques in order to find similar pixels (or areas) in the obtained images. In the case of the micro-Raman technique, however, the usual approach is to perform a single spot analysis of only a few selected positions in order to ultimately identify the material on the basis of the comparison with Raman spectra obtained from reference materials. However, when samples are heterogeneous, imaging is still to be preferred in order to deal with the problem of sampling. With the arrival of a new micro-Raman spectrometer at the UGent laboratories, there was the need to explore the possibilities of Raman imaging. One of the most important aspects of imaging is the time needed for the analysis. Therefore, the influence of different instrumental parameters, such as resolution (low or high) and measuring time per pixel, on the quality of Raman spectra and images was investigated in order to evaluate the possibility of performing fast Raman mappings because of the need to identify the regions of interest on the art object in a more systematic manner. Content Type Journal Article Category Invited paper Pages 1-14 DOI 10.1007/s00339-011-6693-5 Authors A. Deneckere, Research Group Raman Spectroscopy, Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, 9000 Ghent, Belgium B. Vekemans, Research Group X-ray Microspectroscopy and Imaging, Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, 9000 Ghent, Belgium L. Van de Voorde, Research Group X-ray Microspectroscopy and Imaging, Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, 9000 Ghent, Belgium P. De Paepe, Laboratory of Mineralogy and Petrology, Ghent University, Krijgslaan 281, S8, 9000 Ghent, Belgium L. Vincze, Research Group X-ray Microspectroscopy and Imaging, Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, 9000 Ghent, Belgium L. Moens, Research Group Raman Spectroscopy, Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, 9000 Ghent, Belgium P. Vandenabeele, Department of Archaeology, Ghent University, Sint-Pietersnieuwstraat 35, 9000 Ghent, Belgium Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In this study, high density well aligned ZnO nanotubes were grown on glass via a two-step growth-then-etching by simple and template-free hydrothermal method. We used etching procedure to introduce additional zinc interstitial defects in the ZnO nanotubes. The optical properties of the ZnO nanotubes have been investigated by depth-resolved cathodluminescence spectroscopy (DRCLS) which provides information about the physical origin and growth dependence of optically active defects together with their spatial distribution. The DRCLS study gives clear evidence about the enhancement of zinc interstitial defects which are responsible for the violet and decrease of the DL emission in ZnO nanotubes when compared to the as grown ZnO nanorods. We observed a variation in the zinc interstitials along the nanotube depth. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6658-8 Authors M. Y. Soomro, Department of Science and Technology, Campus Norrköping, Linköping University, 60174 Norrköping, Sweden I. Hussain, Department of Science and Technology, Campus Norrköping, Linköping University, 60174 Norrköping, Sweden N. Bano, Department of Science and Technology, Campus Norrköping, Linköping University, 60174 Norrköping, Sweden S. Hussain, Department of Science and Technology, Campus Norrköping, Linköping University, 60174 Norrköping, Sweden O. Nur, Department of Science and Technology, Campus Norrköping, Linköping University, 60174 Norrköping, Sweden M. Willander, Department of Science and Technology, Campus Norrköping, Linköping University, 60174 Norrköping, Sweden Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    We present the use of novel nonlinear imaging, terahertz time-domain spectroscopy and imaging as powerful diagnostic tools for studies of works of art. It is shown that nonlinear imaging offers precise in-depth information, while terahertz imaging can reveal hidden objects and uncover information on highly absorbing organic compounds whose visualization is difficult in other parts of the spectrum. Content Type Journal Article Category Invited paper Pages 1-7 DOI 10.1007/s00339-011-6691-7 Authors G. Filippidis, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, P.O. Box 1527, 71110 Heraklion, Greece M. Massaouti, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, P.O. Box 1527, 71110 Heraklion, Greece A. Selimis, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, P.O. Box 1527, 71110 Heraklion, Greece E. J. Gualda, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, P.O. Box 1527, 71110 Heraklion, Greece J.-M. Manceau, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, P.O. Box 1527, 71110 Heraklion, Greece S. Tzortzakis, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, P.O. Box 1527, 71110 Heraklion, Greece Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Spectrally and lifetime-resolved UV-induced luminescence imaging have been applied to the in situ analysis of Vincent Van Gogh’s painting on paper “Les bretonnes et le pardon de pont Aven”. The in situ investigation revealed the presence of an unusual microsecond green emission from the white painted areas of the watercolour, and this long-lived emission has not been reported in modern paintings by other authors. In order to attribute and suggest an identification of the luminescent pigment, our analysis was integrated with further measurements on commercially available modern white pigments (zinc white, Lithopone white, Blanc Fixe, zinc sulphide, and copper-doped zinc sulphide) and with an in-depth study of the synthesis processes of zinc-based pigments available at the end of the 19th century. Analysis suggested an attribution of the unusual emission from the Van Gogh painting to a particular variety of zinc sulphide pigment, characterized by the presence of copper impurities which were unintentionally introduced in the crystal matrix during its production. The present study is the first application of lifetime imaging for the mapping of long-lived luminescence from the semi-conductor pigment. Content Type Journal Article Pages 1-10 DOI 10.1007/s00339-011-6665-9 Authors D. Comelli, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133 Italy A. Nevin, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133 Italy A. Brambilla, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133 Italy I. Osticioli, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133 Italy G. Valentini, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133 Italy L. Toniolo, Dipartimento di Chimica, Politecnico di Milano, Via Mancinelli 7, Milano, 20133 Italy M. Fratelli, Galleria d’Arte Moderna di Milano, Via Palestro 16, Milano, 20121 Italy R. Cubeddu, IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, 20133 Italy Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Optical properties of chalcogenide glasses belonging to the series (80GeS 2 –20Ga 2 S 3 ) 100− x (CsCl) x with x =0;5;10;15;20 were investigated. The linear refractive indices ( n 0 ) were determined by prism measurements at four wavelengths: 633 nm, 825 nm, 1311 nm, and 1511 nm. Z-scan experiments were performed at 800 nm to measure the non-linear indices ( n 2 ) and the absorption coefficients ( β ). CsCl additions in the base glass (80GeS 2 –20Ga 2 S 3 ) are characterized by a white shift of the transmission in the visible range and a strong decrease of both n 0 and n 2 . As the same time, β is also decreasing and this results in a figure of merit FOM=2 βλ / n 2 that remains relatively low at 800 nm, meaning that this series of highly non-linear glasses should be very suitable for optical switching applications at telecommunication wavelengths. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6668-6 Authors Pascal Masselin, Univ. Lille Nord de France, 59000 Lille, France David Le Coq, Univ. Lille Nord de France, 59000 Lille, France Laurent Calvez, UMR CNRS 6226 “Sciences Chimiques de Rennes”, Equipe “Verres et Céramiques”, Univ. de Rennes 1, 35042 Rennes Cedex, France Elena Petracovschi, UMR CNRS 6226 “Sciences Chimiques de Rennes”, Equipe “Verres et Céramiques”, Univ. de Rennes 1, 35042 Rennes Cedex, France Eric Lépine, UMR CNRS 6226 “Sciences Chimiques de Rennes”, Equipe “Verres et Céramiques”, Univ. de Rennes 1, 35042 Rennes Cedex, France Eugène Bychkov, Univ. Lille Nord de France, 59000 Lille, France Xianghua Zhang, UMR CNRS 6226 “Sciences Chimiques de Rennes”, Equipe “Verres et Céramiques”, Univ. de Rennes 1, 35042 Rennes Cedex, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    This paper illustrates the results of a multidisciplinary study on two white marble statues placed in the San Bruno Church (Calabria—Southern Italy): the ‘Madonna con Bambino’ and ‘San Bruno’ statues. The study, performed by combining different analytical techniques (LA-ICP-MS, CL, SEM-EDS, OM, FT-IR, isotopic ratios of 18 O/ 16 O and 13 C/ 12 C by mass spectrometry), aims to give information on the provenance of the marble, the kinds and causes of decay forms that affect the surface of the statues, and the materials used during some undated renovation works. As regards the “San Bruno” statue, three past undocumented restoration samples were analysed. Two of these samples were made with a mixture of gypsum and white pigments, while the other one is a mixture of lime mortar and white pigments, with the addition of diatomaceous earth. A comparison of the obtained data with bibliographic studies concerning pigments allowed the formulation of some hypotheses about the renovation works: they were probably carried out after the early 800s. For both statues several analyses were carried out to characterise some yellow–brown patinas present on their bases. Wax and calcium oxalate are the main components of the patinas on the statues: the former attributable to the use of wax candles, the latter, probably due to the alteration of organic matter, which may have been used during previous restoration phases. The Mn content, the maximum grain size (MGS) of calcite crystals and the isotopic analyses ( δ 13 C, δ 18 O) confirmed that Carrara white marble was used to sculpt the two statues and their bases. Content Type Journal Article Pages 1-9 DOI 10.1007/s00339-011-6671-y Authors D. Miriello, Dipartimento di Scienze della Terra, Università della Calabria, Via P. Bucci cubo 12B, 87036 Rende, CS, Italy I. Alfano, Dipartimento di Scienze della Terra, Università della Calabria, Via P. Bucci cubo 12B, 87036 Rende, CS, Italy C. Miceli, Dipartimento di Scienze della Terra, Università della Calabria, Via P. Bucci cubo 12B, 87036 Rende, CS, Italy S. A. Ruffolo, Dipartimento di Scienze della Terra, Università della Calabria, Via P. Bucci cubo 12B, 87036 Rende, CS, Italy V. Pingitore, Dipartimento di Fisica, Università della Calabria, Via P. Bucci cubo 33C, 87036 Rende, CS, Italy A. Bloise, Dipartimento di Scienze della Terra, Università della Calabria, Via P. Bucci cubo 12B, 87036 Rende, CS, Italy D. Barca, Dipartimento di Scienze della Terra, Università della Calabria, Via P. Bucci cubo 12B, 87036 Rende, CS, Italy C. Apollaro, Dipartimento di Scienze della Terra, Università della Calabria, Via P. Bucci cubo 12B, 87036 Rende, CS, Italy G. M. Crisci, Dipartimento di Scienze della Terra, Università della Calabria, Via P. Bucci cubo 12B, 87036 Rende, CS, Italy A. Oliva, Dipartimento di Fisica, Università della Calabria, Via P. Bucci cubo 33C, 87036 Rende, CS, Italy M. Lezzerini, Dipartimento di Scienze della Terra, Università di Pisa, Via S. Maria 53, 56126 Pisa, Italy F. De Chirico, MiBAC Soprintendenza per i Beni Storico-Artistici ed Etnoantropologici della Calabria (CS), Via Gian Vincenzo Gravina, 87100 Cosenza, CS, Italy N. Mari, MiBAC Soprintendenza per i Beni Storico-Artistici ed Etnoantropologici della Calabria (CS), Via Gian Vincenzo Gravina, 87100 Cosenza, CS, Italy C. Murat, Restorer, Via Dante Alighieri 16, 89818 Capistrano, VV, Italy Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    An effective finite-element (FE) approach for modeling the structure and the deformation of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) is presented. An individual tube was modeled using a frame-like structure with beam elements. The effect of van der Waals forces, crucial in MWCNTs, was modeled by spring elements. The success of this new carbon nanotube (CNT) modeling approach was verified by comparing the simulation results for single- and multi-walled nanotubes and graphene with other experimental and computational results available in the literature. Simulations of final deformed configurations were in excellent agreement with the atomistic models for various deformations. The proposed approach successfully predicts the experimentally observed values for mechanical behavior of SWCNTs and MWCNTs. The results demonstrated that the proposed FE technique could provide a valuable tool for studying the mechanical behavior of different types of nanotubes, as well as their effectiveness as load-bearing entities in nanocomposite materials. Content Type Journal Article Pages 1-8 DOI 10.1007/s00339-011-6625-4 Authors Ehsan Mohammadpour, Mechanical Engineering Department, Universiti Teknologi PETRONAS, 31750 Seri Iskandar, Perak, Malaysia Mokhtar Awang, Mechanical Engineering Department, Universiti Teknologi PETRONAS, 31750 Seri Iskandar, Perak, Malaysia Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The structural and electronic properties of cubic GaN x As 1− x with N-concentration varying between 0.0 and 1.0 with step of 0.25 were investigated using the full potential–linearized augmented plane wave (FP-LAPW) method. We have used the local density approximation (LDA) and the generalized gradient approximation (GGA) for the exchange and correlation potential. In addition the Engel-Vosko generalized gradient approximation (EVGGA) was used for the band-structure calculations. The structural properties of the binary and ternary alloys were investigated. The electronic band structure, total and partial density of states as well as the electron charge density were determined for both the binary and their related ternary alloys. The energy gap of the alloys decreases when we move from x =0.0 to 0.25; then it increases by a factor of about 1.8 when we move from 0.25 to 0.5, 0.75 and 1.0 using EVGGA. For both LDA and GGA moving from x =0.0 to 0.25 causes the band gap to close, showing the metallic nature of the GaN 0.25 As 0.75 alloy. When the composition of N moves through x =0.25, 0.5, 0.75 and 1, the band gap increases. Content Type Journal Article Pages 1-10 DOI 10.1007/s00339-011-6666-8 Authors H. Baaziz, Physics Department, Faculty of Science, University of M’sila, 28000 M’sila, Algeria Z. Charifi, Physics Department, Faculty of Science, University of M’sila, 28000 M’sila, Algeria Ali Hussain Reshak, School of Complex Systems, FFWP-South Bohemia University, Nove Hrady, 37333 Czech Republic B. Hamad, Physics Department, University of Jordan, Amman, 11942 Jordan Y. Al-Douri, Institute of Nano Electronic Engineering, University Malaysia Perlis, 01000 Kangar, Perlis, Malaysia Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Laser-assisted nano-texturing of W substrates cathodes via ablation in liquid environment is experimentally realized. Two laser sources are used, either a Ti:sapphire femtosecond laser or a Nd:YAG laser with pulse duration of 350 ps. Laser exposure of W results in the formation of hemi-spherical nanostructures situated on top of periodic ripples. Nano-textured thermionic W cathode demonstrates the decrease of the efficient work function by 0.3 eV compared to pristine surface. Content Type Journal Article Category Rapid communication Pages 1-4 DOI 10.1007/s00339-011-6692-6 Authors E. V. Barmina, Wave Research Center of A.M. Prokhorov, General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 119991 Moscow, Russian Federation A. A. Serkov, Wave Research Center of A.M. Prokhorov, General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 119991 Moscow, Russian Federation E. Stratakis, Institute of Electronic Structure and Laser, Foundation for Research & Technology—Hellas, (IESL-FORTH), P.O. Box 1527, Heraklion, 711 10 Greece C. Fotakis, Institute of Electronic Structure and Laser, Foundation for Research & Technology—Hellas, (IESL-FORTH), P.O. Box 1527, Heraklion, 711 10 Greece V. N. Stolyarov, Roentgenprom, 35 Lenin str., Protvino, 1442281 Moscow region, Russia I. N. Stolyarov, Roentgenprom, 35 Lenin str., Protvino, 1442281 Moscow region, Russia G. A. Shafeev, Wave Research Center of A.M. Prokhorov, General Physics Institute of the Russian Academy of Sciences, 38, Vavilov street, 119991 Moscow, Russian Federation Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Chromogenic colour prints are amongst the most unstable materials found in heritage collections as the information-carrying dyes fade appreciably even in the dark. However, image stability is just one of the numerous properties that photographic companies aspire for in their products, along with constant improvements in colour balance and image development. It is shown that these continuous changes can be exploited to model the date a print was developed, as well as dye stability. As a non-destructive analytical technique, near-infrared spectroscopy in conjunction with multivariate data analysis was used to derive models to predict the year of development of a photographic print (Root Mean Square Error of Cross-Validation, RMSECV = 5.4 years) and dye stability (RMSECV = 1.4 Δ E T , i.e. normalised annual colour change). To examine the possibility to extend the lifetime of the valuable objects during storage, the use of oxygen-depleted environments (hypoxia) was also investigated. The results obtained show that hypoxia should not be used as a blanket approach for all chromogenic prints, as some degraded faster in hypoxic conditions than the control samples degraded in air. However, for most samples hypoxic storage turned out to be beneficial. Content Type Journal Article Category Invited paper Pages 1-7 DOI 10.1007/s00339-011-6688-2 Authors Ann Fenech, Centre for Sustainable Heritage, The Bartlett School of Graduate Studies, University College London, Central House, 14 Upper Woburn Place, London, WC1H 0NN UK Matija Strlič, Centre for Sustainable Heritage, The Bartlett School of Graduate Studies, University College London, Central House, 14 Upper Woburn Place, London, WC1H 0NN UK May Cassar, Centre for Sustainable Heritage, The Bartlett School of Graduate Studies, University College London, Central House, 14 Upper Woburn Place, London, WC1H 0NN UK Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    An analysis of guided modes in graphene waveguides in the presence of magnetic-electric barrier is presented. The graphene waveguide is controlled by the gate voltages and the magnetic field by depositing two parallel ferromagnets on a dielectric layer. Both in the classical motion and Klein tunneling cases, the fundamental modes exist with the applied magnetic field. The electron wave propagation can be modulated in two different ways by changing the magnetic intensity or the incident energy. We hope that these characteristics can provide potential applications in the graphene-based waveguide devices. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6663-y Authors Ying He, Department of Physics, College of Sciences, Shanghai University, Shanghai, 200444 China Weide Huang, Department of Physics, College of Sciences, Shanghai University, Shanghai, 200444 China Yanfang Yang, Department of Physics, College of Sciences, Shanghai University, Shanghai, 200444 China Chunfang Li, Department of Physics, College of Sciences, Shanghai University, Shanghai, 200444 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    A tunable negative modulus metamaterial is presented, and it is achieved by adjusting the medium density and an effective volume of a split hollow sphere (SHS). This work comprises experimental and numerical studies. The effects of water/air component and the steel ball on the transmission properties were investigated in the impedance tube system. The experimental results show that the transmission dip has a significant blue-shift with increasing water content, whereas the steel ball has a relatively small influence on the resonant frequency. The simulated results by the finite-element method (FEM) are in agreement with the experimental results. Based on medium parameters among the SHS, acoustic metamaterial (AM) with negative modulus can easily be designed in the expected frequency domain, and it provides a convenient route to tune AMs. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6682-8 Authors Li-Mei Hao, Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710129 P.R. China Chang-Lin Ding, Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710129 P.R. China Xiao-Peng Zhao, Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710129 P.R. China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    A brief introduction to Optical Coherence Tomography (OCT) is presented, stressing the origin of the tomographic signal and the detection methods defining various modalities of the technique. The parameters of the tomographs, such as axial and lateral resolution, wavelength and intensity of the probing light, imaging range, time of examination, and sensitivity are then defined, and a paradigm for interpreting the OCT tomograms provided. The second part of the article comprises a review of the utilisation of OCT for structural examination of artworks, illustrated with some representative results. Applications to the structural imaging of semi-transparent subsurface layers such as varnishes and glazes, of underdrawings and of reverse painting on glass, are described first, and then applications in the examination of the structure and state of preservation of historic glass, jade, glazed porcelain and faience are discussed. Finally, the use of OCT combined with LIBS analysis and laser ablation of surface layers is presented. Content Type Journal Article Category Invited paper Pages 1-13 DOI 10.1007/s00339-011-6687-3 Authors Piotr Targowski, Institute of Physics, Nicolaus Copernicus University, ul. Grudziądzka 5, 87-100 Toruń, Poland Magdalena Iwanicka, Institute for the Study, Restoration and Conservation of Cultural Heritage, Nicolaus Copernicus University, ul. Gagarina 7, 87-100 Toruń, Poland Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    A prototype memristive device has been presented in this paper, for which the top and bottom electrodes have been fabricated through a simple and cost-effective technique, i.e. electrohydrodynamic printing. For deposition of the bottom electrode pattern, a silver ink containing 60 wt% silver by content was subjected to controlled flow through a metal capillary exposed to an electric field at the ambient temperature to generate an electrohydrodynamic jet, thereby depositing uniform patterns of silver on glass substrate at a constant substrate speed. The top electrode has been deposited in a similar fashion. In between the top and bottom electrodes, a uniform layer of ZnO is fabricated using spin-coating technique. The nanoscale ZnO memristor stack has a channel length of 370 μm and channel width of 82 μm. A memristor thus fabricated was characterized and its current voltage curves were analyzed. The device showed a typical nonvolatile resistive switching behavior present in memristor devices thus highlighting the EHD printed patterning as a reliable method for the fabrication of memory devices. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6670-z Authors Kyung Hyun Choi, School of Mechatronics Engineering, Jeju National University, 66 Jejudaehakno, Jeju, 690-756 Republic of Korea Maria Mustafa, School of Mechatronics Engineering, Jeju National University, 66 Jejudaehakno, Jeju, 690-756 Republic of Korea Khalid Rahman, School of Mechatronics Engineering, Jeju National University, 66 Jejudaehakno, Jeju, 690-756 Republic of Korea Bum Ko Jeong, School of Electronic Engineering, Jeju National University, 66 Jejudaehakno, Jeju, 690-756 Republic of Korea Yang Hui Doh, School of Electronic Engineering, Jeju National University, 66 Jejudaehakno, Jeju, 690-756 Republic of Korea Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    A novel chalcone derivative, (2 E )-1-(2,4-di- chloro-5-fluorophenyl)-3-[4-dimethylamino)phenyl]prop-2-en-1-one, abbreviated as NNDC, was prepared and characterized by elemental analyses, infrared (IR) and proton nuclear magnetic resonance ( 1 H NMR) spectrum, and thermal analyses. The NNDC-doped poly(methyl methacrylate) (PMMA) thin films with five different doping concentrations by weight were prepared by using a spin-coating method. Their linear optical properties were investigated by using a prism coupling measuring system. The third-order nonlinear optical properties of NNDC in 1,2-dichloroethane (NNDC/1,2-dichloroethane) solution and NNDC-doped PMMA (NNDC/PMMA) films were investigated by using the laser Z-scan technique with 20 ps pulses at 532 nm. A self-focusing effect was observed from the Z-scan curves for solution and thin films and the nonlinear refractive index of the film increases with the increase of the doping concentration. In addition, nonlinear absorption was negligible for all samples. The magnitude of third-order nonlinear refraction index n 2 and the third-order nonlinear susceptibility χ (3) for thin films were 10 −15  m 2 /W and 10 −9  esu, respectively, which are about three orders larger than that of NNDC/1,2-dichloroethane solution. Some necessary analyses were presented. The results show that this material is a promising candidate for application in the nonlinear optical devices at 532 nm. Content Type Journal Article Pages 1-9 DOI 10.1007/s00339-011-6628-1 Authors Jingwei Chen, School of Information Science and Engineering, Shandong University, Jinan, 250100 China Xinqiang Wang, State Key Laboratory of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan, 250100 China Quan Ren, School of Information Science and Engineering, Shandong University, Jinan, 250100 China P. S. Patil, Department of Physics, K.L.E. Society’s, K.L.E. Institute of Technology, Gokul, Hubli 580030, India Tingbin Li, Department of Materials and Chemical Engineering, Taishan University, Tai’an, 271021 China Hongliang Yang, School of Information Science and Engineering, Shandong University, Jinan, 250100 China Jingnan Zhang, School of Information Science and Engineering, Shandong University, Jinan, 250100 China Guochao Li, School of Information Science and Engineering, Shandong University, Jinan, 250100 China Luyi Zhu, State Key Laboratory of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan, 250100 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Gold (Au) pads for surface finish in electronic package were developed by the inkjet printing method. The Au ink for printing was prepared by Au nanoparticles (NPs) coated with capping molecules of dodecylamine (C 12 H 25 NH 2 ). The microstructures of the inkjet-printed Au films were characterized after sintering in various gas flows. The film sintered in air showed that bonding between NPs was not enough for further grain growth due to the incomplete decomposition of the capping layer. The film sintered under nitrogen (N 2 ) had NPs existing on the surface and the bottom which did not participate in sintering. When the film was sintered under N 2 -bubbled through formic acid (FA/N 2 ), a large portion of the pores were observed to make a holey pancake-like structure of the film. The microstructures of the inkjet-printed Au film became denser with grain growth when Au NPs were sintered under mixed gas flows of FA/N 2 and N 2 . The resistivity of film was 4.79 μΩ cm, about twice the bulk value. Organic analysis showed that about 0.43% of residual organics was left in the film. Therefore, this Au film was chosen for solder ball shear test because the microstructure was denser compared to the films sintered under other gasses such as N 2 or FA/N 2 and less organic residue was found from organic analyses. Even though the film sintered under N 2 showed the best electrical property (4.35 μΩ cm), it was not adopted in the shear test because NPs remaining on the bottom of the film could lead to the poor adhesion between the film and substrate and show low shear strength. The shear force was 8.04 newton (N) on average and the strength was 64 MPa. This shear strength is good enough to substitute the inkjet-printed Au nanoparticulate film for electroplating in electronic package. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6610-y Authors Seonhee Jang, Samsung Electro-Mechanics Co. Ltd., Maetan3-Dong, Yeongtong-Gu, Suwon, Gyunggi-Do 443-743, South Korea Hyejin Cho, Samsung Electro-Mechanics Co. Ltd., Maetan3-Dong, Yeongtong-Gu, Suwon, Gyunggi-Do 443-743, South Korea Seongkoo Kang, Samsung Electro-Mechanics Co. Ltd., Maetan3-Dong, Yeongtong-Gu, Suwon, Gyunggi-Do 443-743, South Korea Sungil Oh, Samsung Electro-Mechanics Co. Ltd., Maetan3-Dong, Yeongtong-Gu, Suwon, Gyunggi-Do 443-743, South Korea Donghoon Kim, Samsung Electro-Mechanics Co. Ltd., Maetan3-Dong, Yeongtong-Gu, Suwon, Gyunggi-Do 443-743, South Korea Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In this work, matrix-assisted pulsed laser evaporation was applied to achieve gentle deposition of polymer thin films onto surface acoustic wave resonators. Polyepichlorhydrin, polyisobutylene and polyethylenimine were deposited both onto rigid substrates e.g. Si wafers as well as surface acoustic wave devices using a Nd-YAG laser (266 nm, 355 nm, 10 Hz repetition rate). Morphological investigations (atomic force microscopy and optical microscopy) reveal continuous deposited polymer thin films, and in the case of polyethylenimine a very low surface roughness of 1.2 nm (measured on a 40×40 μm 2 area). It was found that only for a narrow range of laser fluences (i.e. 0.1–0.3 J/cm 2 in the case of polyisobutylene) the chemical structure of the deposited polymer thin layers resembles to the native polymer. In addition, in the case of polyisobutylene it was shown that the irradiation at 355-nm wavelength produces deviations in the chemical structure of the deposited polymer, as compared to its bulk structure. Following the morphological and structural characterization, only a set of well established conditions was used for polymer deposition on the sensor structures. The surface acoustic wave resonators have been tested using the Network Analyzer before and after polymer deposition. The polymer coated surface acoustic wave resonator responses have been measured upon exposure to various concentrations of dimethylmethylphosphonate analyte. All sensors coated with different polymer layers (polyethylenimine, polyisobutylene, and polyepichlorhydrin) show a clear response to the dimethylmethylphosphonate vapor. The strongest signal is obtained for polyisobutylene, followed by polyethylenimine and polyepichlorhydrin. The results obtained indicate that matrix-assisted pulsed laser evaporation is potentially useful for the fabrication of polymer thin films to be used in applications including microsensor industry. Content Type Journal Article Pages 1-9 DOI 10.1007/s00339-011-6624-5 Authors Alexandra Palla-Papavlu, NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, 077125 Magurele, Romania Valentina Dinca, NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, 077125 Magurele, Romania Maria Dinescu, NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, 077125 Magurele, Romania Fabio Di Pietrantonio, “O.M. Corbino” Institute of Acoustics Italian National Research Council—CNR, Via del Fosso del Cavaliere 100, 00133 Rome, Italy Domenico Cannatà, “O.M. Corbino” Institute of Acoustics Italian National Research Council—CNR, Via del Fosso del Cavaliere 100, 00133 Rome, Italy Massimiliano Benetti, “O.M. Corbino” Institute of Acoustics Italian National Research Council—CNR, Via del Fosso del Cavaliere 100, 00133 Rome, Italy Enrico Verona, “O.M. Corbino” Institute of Acoustics Italian National Research Council—CNR, Via del Fosso del Cavaliere 100, 00133 Rome, Italy Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Arrays of through laser-graphitized microstructures have been fabricated in type IIa single-crystal 1.2-mm-thick diamond plates by multipulse laser irradiation with 10-ps pulses at λ =532 nm wavelength. Raman and photoluminescence (PL) spectroscopy studies of the bulk microstructures have evidenced the diamond transformation to amorphous carbon and graphitic phases and the formation of radiation defects pronounced in the PL spectra as the self-interstitial related center, the 3H center, at 504 nm. It is found that the ultrafast-laser-induced structural modifications in the bulk of single-crystal diamond plates occur along {111} planes, known as the planes of the lowest cleavage energy and strength in diamond. Content Type Journal Article Category Rapid communication Pages 1-5 DOI 10.1007/s00339-011-6645-0 Authors Sergei M. Pimenov, Natural Sciences Center, Prokhorov General Physics Institute, Moscow, 119991 Russia Igor I. Vlasov, Natural Sciences Center, Prokhorov General Physics Institute, Moscow, 119991 Russia Andrey A. Khomich, Natural Sciences Center, Prokhorov General Physics Institute, Moscow, 119991 Russia Beat Neuenschwander, Bern University of Applied Sciences, Engineering & Information Technology, Burgdorf, 3400 Switzerland Martin Muralt, Bern University of Applied Sciences, Engineering & Information Technology, Burgdorf, 3400 Switzerland Valerio Romano, Bern University of Applied Sciences, Engineering & Information Technology, Burgdorf, 3400 Switzerland Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Laser microprocessing of several biopolymers from renewable resources is studied. Three proteinic materials were either extracted from the extracellular matrix like Silk Fibroin/Sericin and collagen, or coming from a commercial source like gelatin. All can find future applications in biomedical experimentation, in particular for cell scaffolding. Films of ∼hundred of microns thick were made by aqueous solution drying and laser irradiation. Attention is paid to the properties making them processable with two laser sources: the ultraviolet and nanosecond (ns) KrF (248 nm) excimer and the infrared and femtosecond (fs) Yb:KGW laser. The UV radiation is absorbed in a one-photon resonant process to yield ablation and the surface foaming characteristics of a laser-induced pressure wave. To the contrary, resonant absorption of the IR photons of the fs laser is not possible and does not take place. However, the high field of the intense I 〉∼10 12  W/cm 2 femtosecond laser pulse ionizes the film by the multiphoton absorption followed by the electron impact mechanism, yielding a dense plasma capable to further absorb the incident radiation of the end of the pulse. The theoretical model of this absorption is described in detail, and used to discuss the presented experimental effects (cutting, ablation and foaming) of the fs laser. The ultraviolet laser was used to perform simultaneous multiple spots experiments in which energetic foaming yields melt ejection and filament spinning. Airborne nanosize filaments “horizontally suspended by both ends” (0.25 μm diameter and 10 μm length) of silk biopolymer were observed upon irradiation with large fluences. Content Type Journal Article Pages 1-11 DOI 10.1007/s00339-011-6639-y Authors S. Lazare, Institut des Sciences Moléculaires (ISM) UMR 5255, Université Bordeaux 1, 351 cours de la Libération, 33405 Talence, France A. Sionkowska, Faculty of Chemistry, Nicolaus Copernicus University, Gagarin 7, 87-100 Toruń, Poland M. Zaborowicz, Institut des Sciences Moléculaires (ISM) UMR 5255, Université Bordeaux 1, 351 cours de la Libération, 33405 Talence, France A. Planecka, Faculty of Chemistry, Nicolaus Copernicus University, Gagarin 7, 87-100 Toruń, Poland J. Lopez, ALPHANOV, Centre Technologique Optique et Lasers, 351 Cours de la Libération, 33405 Talence, France M. Dijoux, ALPHANOV, Centre Technologique Optique et Lasers, 351 Cours de la Libération, 33405 Talence, France C. Louména, ALPHANOV, Centre Technologique Optique et Lasers, 351 Cours de la Libération, 33405 Talence, France M.-C. Hernandez, ALPHANOV, Centre Technologique Optique et Lasers, 351 Cours de la Libération, 33405 Talence, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In this study, we investigate dark current voltage characteristics of GaAs/AlGaAs staircase-like asymmetric multiquantum well structure at various temperatures experimentally. The activation energy is calculated by using Arrhenius plots at different voltages. It is found that the activation energy decreased with increasing electric field. This result is evaluated using a barrier lowering effect which is a combination of geometrical and Poole–Frenkel effects. Measured dark current density–voltage ( J – V ) characteristics compared with the Levine model, 3D carrier drift model and the emission capture model. The best agreement with the experimental results of dark current densities is obtained by the Levine model. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6634-3 Authors E. Altin, Scientific and Technological Research Center, Inonu University, Merkez Kampusu, 44280 Malatya, Turkey M. Hostut, Department of Secondary Education of Science & Maths., Division of Physics Education, Akdeniz University, 07058 Antalya, Turkey Y. Ergun, Department of Physics, Anadolu University, Yunusemre Kampusu, 26470 Eskisehir, Turkey Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Silver nanowires have been fabricated using electrochemical deposition within the confined nanochannels of anodic alumina membrane on aluminum substrate. The characterization of structure, morphology, and composition indicates that the silver nanowires are uniform with about 50 nm diameter corresponding to the pore diameter of the anodic alumina membrane and almost single crystal with preferred growth along the [111] direction. Electrical measurements at room temperature showed that these silver nanowires were high conductive with a conductivity of approximately 0.13×10 5  S/cm. Also, individual silver nanowires were investigated by measuring current as a function of bias voltage until the point of failure. This study will be very useful for the development of future nanoelectronic devices and circuits that employ Ag nanowires. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6635-2 Authors Yitian Peng, Jiangsu Key Laboratory of Design and Manufacture of Micro/nano Biomedical Instrument, Southeast University, Nanjing, 211189 China Quanfang Chen, MEMS and Nanomaterials Lab, Mechanical, Materials and Aerospace Engineering Department, University of Central Florida, Orlando, FL 32816-2450, USA Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Wurtzite ( w ) and zincblende ( zb ) InN films have been grown on (011) SrTiO 3 (STO) substrates by metal-organic chemical vapor deposition, the epitaxial relationships and optical properties are characterized by X-ray diffraction (XRD), absorption and photoluminescence (PL). Based on XRD θ –2 θ and Φ scanning results, the epitaxial relationships between ( w - and zb -) InN films and STO substrates are determined, that is, (0001)[11 2 0] w -InN //(011)[100] STO and . Compared with the w -InN films, the zb -InN films exhibit a red shift in absorption edge and PL spectra, and a much narrower and stronger PL spectrum, implying a better optical quality of zb -InN films. The structure transition is supposed to be due to the difference in atom and bond areal density between the crystal plane of w -InN(0001) and zb -InN(100). Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6644-1 Authors C. H. Jia, Key Laboratory of Semiconductor Materials, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 P.R. China Y. H. Chen, Key Laboratory of Semiconductor Materials, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 P.R. China B. Zhang, Key Laboratory of Semiconductor Materials, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 P.R. China X. L. Liu, Key Laboratory of Semiconductor Materials, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 P.R. China S. Y. Yang, Key Laboratory of Semiconductor Materials, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 P.R. China W. F. Zhang, Key Laboratory of Photovoltaic Materials of Henan Province and School of Physics & Electronics, Henan University, Kaifeng, 475004 P.R. China Z. G. Wang, Key Laboratory of Semiconductor Materials, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083 P.R. China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Porous indium oxide thin film prepared by the dip coating technique has been used in the construction of a field effect transistor. The coating solution was prepared from indium chloride precursor. The average particle size of the dip coated thin film was found to be 25 nm. Scanning electron microscopic images show the porous nature of the film, and the root mean square roughness of the film calculated using atomic force microscope was 24 nm. A transistor has been constructed by evaporating metal Aluminium as source and drain electrodes on the indium oxide active layer and employing the silicon substrate itself as a gate. The sensor response of the constructed transistor was tested with ethanol, ammonia and acetone vapours. The sensor showed good response to ethanol vapours even at 5-ppm level, and the time for response and recovery of the gas was nearly 1 min. Response to ammonia and acetone was comparatively poor. When the gate voltage was increased from 0 to 300 mV, a considerable increase in the source-drain current was observed. As the temperature of the sensing element increased, response to ethanol vapours also increased. There was nearly a linear variation in the transistor response for 100 ppm of ethanol vapours when the gate voltage was swept from 0 to 300 mV. The sensor response of the transistor increases with the gas concentration. The constructed transistor was found to be selectively sensitive to ethanol; therefore it can be implemented to work as a breath alcohol checker. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6655-y Authors M. Seetha, Department of Physics, SRM University, Kattankulathur, Kancheepuram Dt 603203, India D. Mangalaraj, DRDO-BU Centre for Life Sciences, Bharathiar University, Coimbatore, 6410046 India Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    SiC single crystals were implanted with Fe ions and the effects of implantation temperature, Fe concentration, and subsequent swift heavy ion irradiation on both dopant and damage depth distributions were evaluated by using RBS and channelling techniques. It is found that an increase of the implantation temperature above the threshold temperature for amorphization can lead to the formation of a broad layer (∼50 nm) containing a large concentration of implanted Fe atoms (∼2 at.%) but almost free of implantation defects. This particular configuration is likely due to dynamic annealing during implantation combined with defect annihilation at the surface. It is only observed when the implanted species concentration does not exceed a critical value (which lies between 2 and 5 at.% in the present system). Post-implantation swift heavy ion irradiation leads to a further decrease of the damage level, while the Fe distribution is not affected. The Fe substitutional fraction has been evaluated in the different tested conditions. A maximum value of ∼50% is found when implantation is performed at the temperature above that required to prevent amorphization (470 K in the present system). Swift-heavy ion irradiation seems to induce Fe atoms relocation at substitutional positions. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6660-1 Authors A. Declémy, Département de Physique et Mécanique des Matériaux, SP2MI, Téléport 2, Institut Pprime, UPR 3346, CNRS, Université de Poitiers, ENSMA, Boulevard Marie et Pierre Curie, BP 30179, 86962 FUTUROSCOPE-Chasseneuil Cedex, France A. Debelle, Centre de spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Univ. Paris-Sud, CNRS-IN2P3, 91405 Orsay-Cedex, France C. Dupeyrat, Département de Physique et Mécanique des Matériaux, SP2MI, Téléport 2, Institut Pprime, UPR 3346, CNRS, Université de Poitiers, ENSMA, Boulevard Marie et Pierre Curie, BP 30179, 86962 FUTUROSCOPE-Chasseneuil Cedex, France L. Thomé, Centre de spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Univ. Paris-Sud, CNRS-IN2P3, 91405 Orsay-Cedex, France I. Monnet, Centre de Recherche sur les Matériaux, les Ions et la Photonique (CIMAP), CEA-CNRS-ENSICAEN, BP 5133, Bd Henri Becquerel, 14070 Caen Cedex 5, France D. Eyidi, Département de Physique et Mécanique des Matériaux, SP2MI, Téléport 2, Institut Pprime, UPR 3346, CNRS, Université de Poitiers, ENSMA, Boulevard Marie et Pierre Curie, BP 30179, 86962 FUTUROSCOPE-Chasseneuil Cedex, France Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Surface coating effect on field emission performance of ZnO nanowires was studied by zinc surface coating. Coating time was found to play an important role in determining the field emission properties. 3 s and 5 s coating enhanced the field emission properties considerably, with lower turn-on field and larger electron emission current density. Prolonging the coating time to 10 s deteriorated the field emission properties of ZnO nanowires. Surface morphology change and green emission in photoluminescence related surface state were found to be responsible for such improvement. Our results provide an innovative approach to improve the field emission properties of ZnO nanowires for development of vacuum nanoelectronic devices. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6664-x Authors Qing Zhao, State Key Laboratory for Mesoscopic Physics, and Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, 100871 China Rui Zhu, State Key Laboratory for Mesoscopic Physics, and Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, 100871 China Sheng Wang, State Key Laboratory for Mesoscopic Physics, and Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, 100871 China X. F. Rui, Link A Media Devices Corporation, Santa Clara, CA 95051, USA Dapeng Yu, State Key Laboratory for Mesoscopic Physics, and Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, 100871 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In this paper an efficient micromachining of poly(vinylidene fluoride) (PVDF) by direct photo-etching with a laser-plasma EUV (extreme ultraviolet) source was demonstrated for the first time. Mass spectroscopy was employed to investigate the ablation products and revealed emission of numerous molecular species of C-containing fragments of the polymer chain. Chemical surface changes after irradiation were investigated using X-ray photoelectron spectroscopy (XPS). The XPS spectra obtained for PVDF samples, irradiated with low and high EUV fluence, indicate significant differences between chemical structures in near-surface layers. It was shown that irradiation with low fluence results in defluorination and thus carbon enrichment of the polymer in near-surface layer. In contrary, irradiation with high fluence leads to intense material ablation and hardly modifies the chemical structure of the remaining material. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6662-z Authors A. Bartnik, Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland H. Fiedorowicz, Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland R. Jarocki, Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland J. Kostecki, Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland M. Szczurek, Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland P. W. Wachulak, Institute of Optoelectronics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In this paper, we report the effect of gamma ray photons on the electrical conductivity of 100 nm Cu nanowires prepared by the technique of electrodeposition using track-etched membranes. Different fluences of photons have been used to observe the effect and in each case of post-irradiation, electrical conductivity is found to increase in a linear manner with increase in applied potential difference; however the rate of increase of conductivity is different in different cases of radiation fluence. Grain boundary scattering is of significance for the post-irradiation parabolic nature of the I–V characteristics (IVC), which are of a linear pattern following Ohm’s law before irradiation. Increase or decrease in the number of charge carriers during their transport through the nanowires is the result of two competitive processes—specular and diffusive scattering of charge carriers (electrons) from grain boundaries, which are itself a region of high resistance rather than inter-grain regions. The results have been discussed in light of the Mayadas and Shatzkes (MS) model with a slight modification for irradiated nanowires. Content Type Journal Article Pages 1-8 DOI 10.1007/s00339-011-6659-7 Authors Devender Gehlawat, Department of Physics, National Institute of Technology, Kurukshetra, 136119 India R. P. Chauhan, Department of Physics, National Institute of Technology, Kurukshetra, 136119 India R. G. Sonkawade, School of Physical Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, 226025 India S. K. Chakarvarti, Manav Rachna International University/MRCE, Faridabad, India Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    In this article, lasers in the ultraviolet, visible and infrared light spectra working with pulse widths in the nanosecond range are applied to a range of toner-paper combinations to determine their ability to remove toner. If the laser energy fluence can be chosen to stay below the ablation threshold of paper at the same time that it surpasses that of toner, paper could be cleaned and re-used instead of being recycled or disposed into a landfill. This could significantly reduce the environmental impact of paper production and use. Although there are a variety of paper conservation studies which have investigated the effects of laser radiation on blank and soiled paper, none has previously explored toner-print removal from paper by laser ablation. Colour analysis under the L ∗ a ∗ b ∗ colour space and SEM examination of the outcome indicate that it is possible to remove toner from paper without damaging and discolouring the substrate. Best results are obtained when employing visible radiation at a wavelength of 532 nm working with a pulse width of 4 ns and energy fluences under 1.6 J/cm 2 . This means that it is technically feasible to remove toner-print for paper re-use. Content Type Journal Article Category Invited paper Pages 1-18 DOI 10.1007/s00339-011-6654-z Authors D. R. Leal-Ayala, Low Carbon Materials Processing Group, Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ UK J. M. Allwood, Low Carbon Materials Processing Group, Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ UK T. A. M. Counsell, Low Carbon Materials Processing Group, Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ UK Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    This article has presented a novel method to fabricate superhydrophobic metal carboxylate surface on substrates like copper, ferrum, etc. This method markedly shortened the fabrication time to less than one second. The superhydrophobic effect is even better that the contact angle (CA) is 170±1° and the sliding angle (SA) 〈2°. Scanning electron microscopy (SEM) images showed micro-nano flower-like structures. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed that the flower-like structures are composed of Cu[CH 3 (CH 2 ) 12 COO] 2 . The ethanol solution containing fatty acid and metal salt plays a key role in this method. This method has tremendous potentials in industrial production of superhydrophobic materials. Content Type Journal Article Pages 1-6 DOI 10.1007/s00339-011-6657-9 Authors Feng Li, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710129 China Xingguo Geng, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710129 China Zhi Chen, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710129 China Lei Zhao, Department of Applied Physics, Northwestern Polytechnical University, Xi’an, 710129 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Fe/Fe 3 C-functionalized carbon nanotubes (CNTs) have been prepared by the floating catalyst chemical vapor-deposition method. It is demonstrated that the Fe and Fe 3 C nanostructures are both encapsulated in the CNTs or decorated on the surface of CNTs. The Fe/Fe 3 C content in the composites can easily be adjusted by changing the ferrocene concentration in the preparation. The electromagnetic properties of the CNTs have been evaluated in the frequency range of 2–18 GHz, and the nanocomposites exhibit excellent microwave absorbing performance. The CNT composites with higher Fe/Fe 3 C content show enhanced microwave reflection losses. The significant influence of the Fe/Fe 3 C nanostructures on the microwave absorption is realized by tuning the characteristic impedance of the nanocomposites. With increasing thickness, the maximum reflection loss peak shifts to lower frequency. The microwave absorbing performance of the composites is mainly caused by dielectric loss, resulting from the continuous CNT networks with excellent electrical conductivity. Content Type Journal Article Pages 1-7 DOI 10.1007/s00339-011-6641-4 Authors Qingmei Su, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, 321004 China Guo Zhong, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, 321004 China Jie Li, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, 321004 China Gaohui Du, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, 321004 China Bingshe Xu, Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan, 30024 China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    Multispectral imaging has been applied to the field of art conservation and art history since the early 1990s. It is attractive as a non-invasive imaging technique because it is fast and hence capable of imaging large areas of an object giving both spatial and spectral information. This paper gives an overview of the different instrumental designs, image processing techniques and various applications of multispectral and hyperspectral imaging to art conservation, art history and archaeology. Recent advances in the development of remote and versatile multispectral and hyperspectral imaging as well as techniques in pigment identification will be presented. Future prospects including combination of spectral imaging with other non-invasive imaging and analytical techniques will be discussed. Content Type Journal Article Category Invited paper Pages 1-15 DOI 10.1007/s00339-011-6689-1 Authors Haida Liang, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS UK Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The surface transport properties of naturally oxidized p-type Hg 0.776 Cd 0.224 Te thin film were investigated in the magnetic-field region 0–14 T and in the temperature region 8–300 K. The Hall electron concentration increases with temperature, while the surface concentration of the two-dimensional electrons in the naturally oxidized surface, calculated by Shubnikov–de Haas oscillations, decreases as temperature increases at temperatures below 20 K. The contradiction and the extraordinary quantum Hall filling factors are accounted for by assuming extra bulk-like electrons in the surface region, which dominate the surface transport properties at temperatures over 8 K. Content Type Journal Article Pages 1-5 DOI 10.1007/s00339-011-6672-x Authors T. Lin, National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Science, Tu Tian Road 500, Shanghai 200083, China L. Y. Shang, Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai, 200062 China W. Z. Zhou, College of Physics Science and Technology, Guangxi University, Nanning, Guangxi 530004, China X. J. Meng, National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Science, Tu Tian Road 500, Shanghai 200083, China J. L. Sun, National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Science, Tu Tian Road 500, Shanghai 200083, China G. Yu, National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Science, Tu Tian Road 500, Shanghai 200083, China S. L. Guo, National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Science, Tu Tian Road 500, Shanghai 200083, China J. H. Chu, National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Science, Tu Tian Road 500, Shanghai 200083, China Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396

Description:    The neck growth in the laser sintering of different-sized gold (100) nanoparticles under different heating rates is investigated using a molecular dynamics method. The numerical simulations are carried out for four pairs of two spherical nanoparticles under three different heating rates. For each pair, one nanoparticle has the same diameter of 4 nm and the other nanoparticle’s diameter is varied, ranging from 4 nm to 20 nm. The results show that the solid state sintering automatically takes place by local potential at room temperature. The stable neck width increases as the size of the other nanoparticle increases. Once the limit stable neck width is reached, it no longer is affected by the nanoparticle size. For the subsequent laser heating to the same final temperature, a lower heating rate results in a larger stable neck width due to the longer sintering process. The neck growth mechanisms and rate under various sintering conditions are discussed. Content Type Journal Article Pages 1-11 DOI 10.1007/s00339-011-6680-x Authors Lingqi Yang, Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211, USA Yong Gan, Department of Engineering Mechanics, Zhejiang University, Zhejiang, 310027 China Yuwen Zhang, Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211, USA J. K. Chen, Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211, USA Journal Applied Physics A: Materials Science & Processing Online ISSN 1432-0630 Print ISSN 0947-8396