ALBERT

Description:    A Ce-based intermetallic compound Ce 2 CuGe 6 and its La analogue La 2 CuGe 6 were synthesized and examined by X-ray powder diffraction, electrical resistivity, magnetic susceptibility, X-ray absorption spectrum and specific-heat measurements. The results reveal that Ce 2 CuGe 6 is an antiferromagnetic Kondo-lattice compound with T N ∼15 K. The effective moment deduced from paramagnetic region is 2.58  μ B per cerium ion, which is close to localized Ce 3+ free ion in 2 F 5/2 state. X-ray absorption measurement also precluded the existence of an intermediate valence state. The magnetic entropy calculated from heat capacity specific-heat measurement suggested a doublet ground state. In addition, we also observed a spin-glass-like behavior in this material. The spin-glass-like behavior might be due to the complex interplay between magnetic interactions. Content Type Journal Article Pages 1-5 DOI 10.1007/s10948-011-1158-9 Authors J. J. Lu, Nano-Technology R&D Center, Kun Shan University, Tainan, Taiwan T. S. Mo, Nano-Technology R&D Center, Kun Shan University, Tainan, Taiwan K. J. Gan, Department of Electrical Engineering, National Chiayi University, Chiayi, Taiwan J. F. Chou, Nano-Technology R&D Center, Kun Shan University, Tainan, Taiwan M. K. Lee, Department of Physics, National Cheng Kung University, Tainan, 700 Taiwan Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    By applying Monte Carlo simulations in the canonical ensemble, investigation of the magnetic properties of Fe/Cu multilayers is carried out in comparison with Mössbauer experimental results. From differing relaxation rates for spins with few near-neighbor spins and particularly those located at the interface, the Mössbauer result can be simulated. Our model consists of an alternate stacking of iron and copper layers (Fe n Fe /Cu n Cu ) with disordered interface. The simulation results confirm that the concentration of interface alloys (Fe 1− x Cu x ), measurement temperature and magnetic layer thickness modify systemically the magnetization distribution in the Fe/Cu multilayers. The result is compared with Mössbauer experimental analysis. Meaningful results are obtained by analysing the dynamical microscopic behaviour of individual spins. Content Type Journal Article Pages 1-6 DOI 10.1007/s10948-011-1140-6 Authors A. Razouk, Laboratoire de Physique et Mécanique des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, BP 523, 23000 Beni-Mellal, Morocco M. Sahlaoui, Laboratoire de Physique et Mécanique des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, BP 523, 23000 Beni-Mellal, Morocco M. Sajieddine, Laboratoire de Physique et Mécanique des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, BP 523, 23000 Beni-Mellal, Morocco Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Hafnium was used as a softener dopant to replace at magnesium sites of Mg 1− x Hf x B 2 regime (where x =0.0, 0.05, 0.1, 0.2, and 0.4 mole). Samples were prepared via high temperature solid state reaction technique depending upon diffusion mechanism of Mg-vapor ions through hafnium–boron matrix. The maximum solubility limit of hafnium ( n ) was found to be ∼0.22 mole. The crystalline lattice constants exhibit slight elongation in the case of the c -axis as x increases. Furthermore, the effect of Hf-doping on the microstructure properties of the MgB 2 system was investigated carefully. The SE-microscopic analysis indicated that hafnium ions diffuse regularly through surface and bulk in case of ( x =0.05–0.2 mole). The grain size was estimated and found to be between 0.33 and 1.34 μm. The mechanical tensile strength of the samples was clearly improved linearly as Hf-content increased, recording the maximum tensile strength of 34.8 MPa for the sample with x =0.4 mole. A visualization of the Hf-doped MgB 2 structure was constructed and investigated to confirm the success of hafnium substitutions at the Mg-sites of the MgB 2 superconductor. Content Type Journal Article Pages 1-9 DOI 10.1007/s10948-011-1134-4 Authors Khaled M. Elsabawy, Chemistry Department, Faculty of Science, Tanta University, Tanta, 31725 Egypt Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We explain several anomalous phenomena observed in the pseudogap phase of hole-doped cuprates based on the recently proposed spin-vortex superconductivity theory. In this theory, doped-holes become almost immobile small polarons, and spin-vortices are formed with those small polarons as their centers. A Hartree–Fock field for conduction electrons that is optimized for the interaction energy of local moments is derived; it contains a fictitious magnetic field arising from spin-vortices, and yields current carrying states. The obtained currents are loop currents around spin-vortices, i.e., the spin-vortex-induced loop currents (SVILCs), and a collection of them produces a macroscopic current. The SVILC explains (1) nonzero Kerr rotation in zero-magnetic field after exposed in a strong magnetic field; (2) the change of the sign of the Hall coefficient with temperature change; (3) the suppression of superconductivity in the x =1/8 static-stripe ordered sample; and (4) a large anomalous Nernst signal, including its sign-change with temperature change. We show that the hourglass-shaped magnetic excitation spectrum is the evidence for the existence of spin-vortices. We further argue that the “Fermi-arc” in the ARPES is a support for the presence of localized moments in the bulk; a disconnected arc-shaped Fermi surface is obtained by assuming an antiferromagnetic interaction between the localized moments in the bulk and itinerant electrons in the surface region. Content Type Journal Article Pages 1-15 DOI 10.1007/s10948-011-1194-5 Authors Ryo Hidekata, Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan Hiroyasu Koizumi, Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Epitaxial growth of CeO 2 buffer layers on biaxially textured (001)Ni tapes was studied using pulsed laser deposition. Relationships between microstructure and deposition parameters were systematically studied in order to develop reliable long tape coating processes. It was found that orientation and texture of CeO 2 buffer layers were sensitive to deposition parameters. X-ray diffraction analyses showed that CeO 2 buffer layers had pure (001) orientation at 860 °C. Under optimized deposition conditions, highly (001) oriented CeO 2 buffer layers have been achieved at a high deposition rate of 1.5 nm/s in-plane texture and out-plane texture of CeO 2 buffer layers were 4.25 degrees and 5.85 degrees, respectively. Content Type Journal Article Pages 1-5 DOI 10.1007/s10948-011-1172-y Authors Ying Wang, Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics, Shanghai Jiao Tong University, 800# Dong Chuan Road, Shanghai, 200240 P.R. China Linfei Liu, Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics, Shanghai Jiao Tong University, 800# Dong Chuan Road, Shanghai, 200240 P.R. China Huaran Liu, Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics, Shanghai Jiao Tong University, 800# Dong Chuan Road, Shanghai, 200240 P.R. China Xiaokun Song, Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics, Shanghai Jiao Tong University, 800# Dong Chuan Road, Shanghai, 200240 P.R. China Dan Hong, Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics, Shanghai Jiao Tong University, 800# Dong Chuan Road, Shanghai, 200240 P.R. China Da Xu, Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics, Shanghai Jiao Tong University, 800# Dong Chuan Road, Shanghai, 200240 P.R. China Shengping Zhu, Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics, Shanghai Jiao Tong University, 800# Dong Chuan Road, Shanghai, 200240 P.R. China Yijie Li, Key Laboratory of Artificial Structure and Quantum Control, Ministry of Education, Department of Physics, Shanghai Jiao Tong University, 800# Dong Chuan Road, Shanghai, 200240 P.R. China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    By applying Monte Carlo simulations in the canonical ensemble, investigation of the magnetic properties of Fe/Cu multilayers is carried out in comparison with Mössbauer experimental results. From differing relaxation rates for spins with few near-neighbor spins and particularly those located at the interface, the Mössbauer result can be simulated. Our model consists of an alternate stacking of iron and copper layers (Fe n Fe /Cu n Cu ) with disordered interface. The simulation results confirm that the concentration of interface alloys (Fe 1− x Cu x ), measurement temperature and magnetic layer thickness modify systemically the magnetization distribution in the Fe/Cu multilayers. The result is compared with Mössbauer experimental analysis. Meaningful results are obtained by analysing the dynamical microscopic behaviour of individual spins. Content Type Journal Article Pages 1-6 DOI 10.1007/s10948-011-1140-6 Authors A. Razouk, Laboratoire de Physique et Mécanique des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, BP 523, 23000 Beni-Mellal, Morocco M. Sahlaoui, Laboratoire de Physique et Mécanique des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, BP 523, 23000 Beni-Mellal, Morocco M. Sajieddine, Laboratoire de Physique et Mécanique des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, BP 523, 23000 Beni-Mellal, Morocco Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The compounds Gd 1− x Nd x BaSrCu 3 O 7− δ (where x =0, 0.1 and 0.2) and Gd 1− x Dy x BaSrCu 3 O y (where x =0, 0.1 and 0.3) were synthesized using the solid state reaction technique. The tetragonal crystallization of the compounds was identified by powder X-ray diffraction. The microrange crystallite formation and the substitution elements present in the compounds were observed by SEM and EDX analyses. The suppression of superconducting transition temperature and the variation of magnetization parameters for the substitution of rare-earth magnetic elements Nd and Dy ions were observed by low-temperature electrical resistance and magnetization measurements. Content Type Journal Article Pages 1-8 DOI 10.1007/s10948-011-1137-1 Authors A. Manigandan, Department of Physics, Anna University Chennai, Chennai, 600025 India V. Anbarasu, Department of Physics, Anna University Chennai, Chennai, 600025 India K. Sivakumar, Department of Physics, Anna University Chennai, Chennai, 600025 India Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Here, the superconducting and AC/DC magnetic properties of REBa 2 Cu 3 O 7− δ (RE: Eu, Gd, Ho and Er) are investigated in order to understand the inter-granular and intra-granular behavior of these compounds. These compounds were prepared by standard solid-state reaction route. ErBa 2 Cu 3 O 7− δ (Er-123) and HoBa 2 Cu 3 O 7− δ (Ho-123) (consisting of heavier rare earth) show higher orthorhombic splitting in their XRD patterns than those observed for EuBa 2 Cu 3 O 7− δ (Eu-123) and GdBa 2 Cu 3 O 7− δ (Gd-123) (consisting of lighter rare earth). Even though Eu, Gd, Ho and Er are magnetic elements, substitution of these at Y site in Y-123 does not change the superconducting transition temperature ( T c ). Er-123 and Ho-123 exhibit very sharp superconducting transition while Eu-123 and Gd-123 exhibit relatively broad transition with little hump at the lower part of transition close to the long-range superconducting state with zero resistance. In addition to that, Eu-123 and Gd-123 show relatively higher normal state resistivity than those of Er-123 and Ho-123. The AC susceptibility measurements reveal that these compounds possess different strength of inter-granular couplings. The hump in the superconducting transition of Eu and Gd is not due to the lack of inter-grain couplings in these samples because of having better grain connectivity in the samples as compared to other rare earth elements in REBa 2 Cu 3 O 7− δ system. Though intra-grain peak is insensitive to the applied magnetic field, inter-grain peak is sensitive to the applied magnetic field. Content Type Journal Article Pages 1-7 DOI 10.1007/s10948-011-1139-z Authors N. P. Liyanawaduge, Industrial Technology Institute, P.O. Box 363, Baudhaloka Mawatha, Colombo 07, Sri Lanka Anuj Kumar, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi, 110012 India B. S. B. Karunarathne, University of Peradeniya, Peradeniya, 20400 Sri Lanka Amita Malik, Dyal Singh College, Lodhi Road, New Delhi, 110003 India H. Kishan, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi, 110012 India V. P. S. Awana, National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi, 110012 India Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The present issue of Journal of Superconductivity and Novel Magnetism collects the papers presented at the International Conference on “Quantum Phenomena in Complex Matter.” Superstripes 2010 held in Erice, Italy, from July 19 to 25, 2010, at the Ettore Majorana Foundation and Centre for Scientific Culture. In this preface, I discuss the scientific scenario of the search for the mechanism of the macroscopic quantum coherent phase at high temperature “superconductivity in complexity.” Content Type Journal Article Pages 1-5 DOI 10.1007/s10948-011-1142-4 Authors Antonio Bianconi, Physics Department, Sapienza University of Rome, P. le Aldo Moro 2, 00185 Rome, Italy Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Bi 1− x Eu x FeO 3 ( x =0.00–0.15) ceramics were synthesized by solid state reaction method with rapid liquid phase sintering process at different europium content and the microstructure and electrical properties of the samples were investigated. X-ray diffraction (XRD) studies show that europium substitution has changed the structure of BiFeO 3 from rhombohedral R3c to orthorhombic Pnma and decreased the impurity phase. Raman spectra results also conform that a structure transition occurs at about x =0.20, and indicate that the Eu substitution at Bi site can obviously affect the Bi–O bond. Impedance analyzer measurements show that both dielectric constant and dielectric loss are strongly dependent on the Eu content. The dielectric constant of the Bi 1− x Eu x FeO 3 increases with increasing Eu content from 0.00 to 0.20, then decreases with increasing Eu content from 0.20 to 0.30. The dielectric constant measured at 100 Hz is 542.0 for the x =0.20 sample, which is about 8.5 times as big as that for unsubsitituted BiFeO 3 . The dielectric loss can be effectively decreased by the substitution of Eu for Bi. In addition, the leakage current measurements show that the substitution of Eu can effectively reduce the leakage current density of BiFeO 3 . Content Type Journal Article Pages 1-7 DOI 10.1007/s10948-011-1216-3 Authors Haiyang Dai, Department of Technology and Physics, Zhengzhou University of Light Industry, Zhengzhou, 450002 China Tao Li, Department of Technology and Physics, Zhengzhou University of Light Industry, Zhengzhou, 450002 China Renzhong Xue, Department of Technology and Physics, Zhengzhou University of Light Industry, Zhengzhou, 450002 China Zhenping Chen, Department of Technology and Physics, Zhengzhou University of Light Industry, Zhengzhou, 450002 China Yuncai Xue, Department of Technology and Physics, Zhengzhou University of Light Industry, Zhengzhou, 450002 China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Doped cuprates are inhomogeneous superconductors. The concept of an intrinsic critical temperature, , whose value greatly exceeds that for the resistive , is supported by a number of experimental studies, including those performed recently. These data are discussed in this review. The anomalous diamagnetism observed at is a manifestation of the presence of superconducting clusters embedded into a normal metallic matrix. The value of intrinsic critical temperature in some cuprates reaches a value which is close to room temperature. The a.c. properties of such inhomogeneous systems are discussed. Content Type Journal Article Category Review Paper Pages 1-6 DOI 10.1007/s10948-011-1308-0 Authors Vladimir Z. Kresin, Lawrence Berkeley National Laboratory, University of California at Berkeley, Berkeley, CA 94720, USA Stuart A. Wolf, Departments of Physics and Materials Sciences, University of Virginia, Charlottesville, VA 22904, USA Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The magnetic relaxation phenomenon is a crucial subject for the engineering applications of bulk high-temperature superconductors (HTS) in which the trapped field or levitation force behaves with a time-dependent decay due to the intrinsic flux creep inside the HTS materials. To fully exploit the high trapped field of bulk HTS, we have experimentally investigated the trapped flux relaxation properties, especially at different magnetization levels. With different excitation fields, the dependence between trapped field and relaxation rate was analyzed and compared in both field-cooling magnetization (FCM) and zero-field-cooling magnetization (ZFCM) conditions. In parallel, the relaxation rates for different trapped flux can be measured all at once during a single magnetization process. The relaxation rate is closely correlated to the trapped field and useful to reflect the effect of the following remagnetization processes. To suppress the relaxation, we further checked possible methods from the three aspects of material improvement, working temperature and flux annealing effect. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10948-011-1312-4 Authors Z. Deng, Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo, 135-8533 Japan K. Tsuzuki, Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo, 135-8533 Japan M. Miki, Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo, 135-8533 Japan B. Felder, Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo, 135-8533 Japan S. Hara, Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo, 135-8533 Japan M. Izumi, Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo, 135-8533 Japan Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The “negative-U model” is analyzed and applied to Tl- and In-doped lead telluride, Pb 1− x Tl x Te, and Pb 1− x In x Te, respectively. The former, but not the latter, is superconducting ( T c 〈1.5 K) in a certain concentration range ( x c 〉0.003). At very low concentrations, carriers are created in the valence band and the conductivity is metallic, of the ordinary kind. Matsushita et al. and Erickson et al. explain this as due to disproportionation 2Tl 2+ →Tl + and Tl 3+ . The latter authors are of the opinion that indium also disproportionates in the same way as thallium. If this would be the case, it would be hard to explain the absence of superconductivity at indium doping. In this paper it is shown that In 2+ does not disproportionate under the given circumstances. The Hubbard model, extended and generalized, is therefore consistent with all experimental results. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-011-1309-z Authors Sven Larsson, Department of Chemistry, Chalmers University of Technology, 412 96 Göteborg, Sweden Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    High temperature superconducting (HTS) magnetic levitation (maglev) vehicle is a fascinating transportation tool due to its unique inherent stability. In order to improve performance of present HTS maglev vehicle system, a novel HTS maglev vehicle (aero-vehicle) utilizing aerodynamic designs from modern aircraft is proposed, which is driven by an engine positioned on the top of the car body. The aerodynamic designs of the aero-vehicle include the wings and the empennage, and these new designs are used to adjust and control the pitch, roll, and yaw of the car body. To analyze the feasibility of the aero-vehicle, its characteristics are investigated in the paper. Depending on ailerons of wings, elevator and rudder of the empennage, the aero-vehicle is capable to advance safety and ride comfort of present HTS maglev vehicle. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-011-1315-1 Authors D. H. Jiang, Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, Sichuan 610031, P.R. China J. S. Wang, Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, Sichuan 610031, P.R. China Q. X. Lin, Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, Sichuan 610031, P.R. China G. T. Ma, Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, Sichuan 610031, P.R. China S. Y. Wang, Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, Sichuan 610031, P.R. China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    This study deals with the effect of Mn addition on the structural and superconducting properties of Bi 1.8 Pb 0.4 Sr 2 Mn x Ca 2.2 Cu 3.0 O y ceramics with x =0,0.03,0.06,0.15,0.3 and 0.6 by means of X-ray analysis (XRD), scanning electron microscopy (SEM), electron dispersive X-ray (EDX), resistivity, and transport critical current density ( J c ) measurements. Zero-resistivity transition temperatures ( T c ) of the samples produced via the standard solid-state reaction method are estimated from the dc resistivity measurements. Moreover, the phase fraction and lattice parameters are determined from XRD measurements while the microstructure, surface morphology and element composition analyses of the samples are investigated by SEM and EDX measurements, respectively. It is found that T c values are obtained to decrease from 109 K to 85 K; likewise, J c values are observed to reduce from 3200 A/cm 2 to 125 A/cm 2 with increasing Mn addition. According to the refinement of cell parameters done by considering the structural modulation, the Mn addition is confirmed by both an increase of the lattice parameter a and a decrease of the cell parameter c of the samples in comparison with that of the pure sample (Mn0). SEM measurements show that not only the surface morphology and grain connectivity are seen to degrade but the grain sizes of the samples are found to decrease with the increase of the Mn addition as well. The EDX results reveal that the elements used for the preparation of samples distribute homogeneously and the Mn atoms enter into the crystal structure by replacing Sr and Cu atoms. The possible reasons for the obtained degradation in microstructural and superconducting properties are also interpreted. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10948-011-1324-0 Authors G. Yildirim, Department of Physics, Abant Izzet Baysal University, Bolu, 14280 Turkey S. Bal, Department of Physics, Abant Izzet Baysal University, Bolu, 14280 Turkey E. Yucel, Department of Physics, Mustafa Kemal University, Hatay, 31034 Turkey M. Dogruer, Department of Physics, Abant Izzet Baysal University, Bolu, 14280 Turkey M. Akdogan, Department of Physics, Abant Izzet Baysal University, Bolu, 14280 Turkey A. Varilci, Department of Physics, Abant Izzet Baysal University, Bolu, 14280 Turkey C. Terzioglu, Department of Physics, Abant Izzet Baysal University, Bolu, 14280 Turkey Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Stability functions are an important analytical/numerical tool for appropriate design of conductor geometry and dimensions to prevent conductor losses under a transport current. While standard stability calculations following the Stekly, adiabatic, or dynamic stability models apply purely solid thermal conduction mechanism and derive results under (quasi) stationary conditions, the present paper investigates if, and to which extent, also radiation heat transfer, in addition to solid conduction, can exert impacts on conductor stability. Further, the full transient conductor temperature evolution after a disturbance is calculated. The analysis applies an interplay between Monte Carlo radiative transfer calculations, to describe absorption of heat pulses and their distribution in the conductor, and a rigorous finite element method to calculate the resulting temperature field and stability functions. The results show that radiative heat transfer cannot be neglected in particular if periodic disturbances have to be considered that can arise, e.g., in a flux flow fault current limiter. Content Type Journal Article Category Original Paper Pages 1-12 DOI 10.1007/s10948-011-1314-2 Authors Harald Reiss, Department of Physics, University of Wuerzburg, Am Hubland, 97074 Wuerzburg, Germany Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In recent years, all modern vehicles and transport means use a vast variety of sensors and transducers. The operation of all medical instruments is also based on sensors and transducers. Industry is also employing more and more transducers for the monitoring and control of production lines. Therefore, the sensing technology has been driven by the increasing needs for enhanced sensitivity, improved stability, high reliability, and lower costs. For this purpose, we have proposed and developed novel two LC resonant-type magnetoimpedance (LCMI) sensor devices utilizing soft magnetic microwires as a sensing element, giving an emphasis on the use of resonance effect from LC-components and the rapid permeability change of the magnetic microwires to significantly improve the sensitivity performance of sensors. This article aims to provide a comprehensive analysis of the design and operation of these devices. After a description of magnetic core materials, circuit designs and fabrication techniques is given, the details of all experimental measurements are presented. The characterizations of constructed LCMI sensor devices are systematically analyzed, and the physical origins of magneto-resonant phenomena, field, and frequency dependences in these LCMI sensor devices are addressed. Influences of processing parameters on the sensing characteristics of LCMI sensors are also discussed. This enables the optimal conditions to fabricate high-performance magnetic sensing devices. Content Type Journal Article Category Review Paper Pages 1-15 DOI 10.1007/s10948-011-1320-4 Authors Anh-Tuan Le, Department of Nanoscience and Nanotechnology, Hanoi University of Science and Technology (HUST), 01 Dai Co Viet street, Hanoi, Vietnam Manh-Huong Phan, Functional Materials Laboratory, Department of Physics, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620, USA Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In this work, single-crystal samples 20 mm in diameter were grown by a cold top-seeding method. In order to study the effect of an Y 2 O 3 buffer layer, a compacted precursor was located in a crucible on a buffer layer of freely poured Y 2 O 3 powder. The YBCO bulk samples were carefully prepared in the same chemical composition. In order to examine the homogeneity of the samples, rectangular specimens were cut from a sample. The structural orientation of the specimens was measured by a X-ray diffractrometer (XRD). The microstructure was observed with a Scanning Electron Microscope (SEM). The magnetic properties were measured using a Vibrating Sample Magnetometer (VSM) at 77 K with the applied magnetic field parallel to the c -axis. As a result only (00 l ) peaks were observed in X-ray diffraction data, indicating that all specimens are highly oriented with the c -axis perpendicular to the top surface. Also the cut samples exhibited very fine Y211 inclusion distributed in the bulk sample observed in SEM micrographs. The critical current density J c (A/cm 2 ) has been estimated by the extended Bean model. The maximum value of the critical current density at 77 K is 5.2×10 4  A/cm 2 in a self-field. The trapped magnetic field measurements of the samples were performed by using Hall probe scanning device with static field of 0.5 T at 77 K. The single-domain sample exhibits a trapped field of 1140 G at 77 K. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10948-011-1325-z Authors Alev Aydıner, Physics Department, Karadeniz Technical University, 61080 Trabzon, Turkey Bakiye Çakır, Physics Department, Artvin Çoruh University, 08000 Artvin, Turkey Mehmet Başoğlu, Physics Department, Karadeniz Technical University, 61080 Trabzon, Turkey Hironori Seki, Shibaura Institute of Technology, 3-7-5, Toyoshu, Koto-ku, Tokyo, 135-8548 Japan Atikorn Wongsatanawarid, Mechanical Engineering Department, King Mongkut’s University of Technology Thonburi, 126 Prachautit Rd., Bangmod, Thungkru, Bangkok, 10140 Thailand Masato Murakami, Shibaura Institute of Technology, 3-7-5, Toyoshu, Koto-ku, Tokyo, 135-8548 Japan Ekrem Yanmaz, Physics Department, Karadeniz Technical University, 61080 Trabzon, Turkey Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    A systematic study on the synthesis of carbon-doped MgB 2 superconductor, using a new approach wherein the sample was treated under both pressed carbon environment as well as flowing argon, is presented. The sample synthesized was found to be compact and showed cannibalistic surface morphology. Carbon doping in the sample, crystallized in hexagonal structure, accounted for the reduced in-plane lattice parameter of 3.06 Å. The intraband scattering due to doping of carbon resulted in a decreased superconducting transition at about 29 K. The behavior of resistivity with respect to a decrease in temperature was embedded in the signatures for the scattering of electrons by phonons as well as the grain boundary impurity in the sample. The carbon doping achieved by the proposed synthesis technique showed improvement in the self-field critical current density up to around 10 5  A/cm 2 at 5 K. The flux-pinning plots were studied to understand the dominant pinning mechanism in the sample. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10948-011-1330-2 Authors B. B. Sinha, Korea Institute of Materials Science, 797 Changwondaero, Changwon, 642-831 Korea K. C. Chung, Korea Institute of Materials Science, 797 Changwondaero, Changwon, 642-831 Korea S. H. Pawar, Department of Technology, Center for Interdisciplinary Research, D.Y. Patil University, Kolhapur, 416 006 India S. X. Dou, Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW2500 Australia Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In this research, barium ferrite /magnetite nanocomposites synthesized via a mechano-chemical route. Graphite was used in order to reduce hematite content of barium ferrite to magnetite to produce a magnetic nanocomposite. The effects of processing conditions on the powder characteristics were investigated by XRD, VSM, and HRTEM techniques. XRD results revealed that milling under air and argon atmospheres resulted in the appearance of Fe 3 O 4 peaks beside BaFe 12 O 19 peaks after 15 and 20 hrs milling, respectively. The intensity of Fe 3 O 4 peaks in the XRD patterns increased by increasing the milling time. VSM studies revealed that saturation magnetization of the 40-hrs milled samples under air and argon atmospheres was 31.25 and 36.42 emu/g, respectively. This difference might be due to more Fe 3 O 4 content in the latter sample. By annealing of the 40-hrs milled sample in air, saturation magnetization increased to 139.12 emu/g. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10948-011-1322-2 Authors M. J. Molaei, School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran, Iran A. Ataie, School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran, Iran S. Raygan, School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box: 14395-553, Tehran, Iran S. J. Picken, Nanostructured Materials (NSM), Faculty of Applied Sciences, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands F. D. Tichelaar, National Center for HREM, Kavli Institute of Nanoscience, Delft University of Technology, Rotterdamseweg 137, 2628 AL Delft, The Netherlands Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The levitation force between a permanent magnetic disk and a thin superconducting disk in the Meissner state is calculated using the dipole–dipole interactions model. The levitation force as a function of the magnet and superconductor radii, the levitation height, and the superconductor thickness is studied under the assumption that the radius of the magnet is much smaller than the radius of the superconductor. Results showed an increase in the levitation force as a function of the radius of the superconducting disk. However, the levitation force decreases as the radius of the permanent magnetic disk increases. Demagnetizing effects are taken into account by considering the appropriate demagnetizing factor for the suggested system. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-011-1283-5 Authors F. Y. Alzoubi, Department of Physics, Jordan University of Science and Technology, Irbid, Jordan M. K. Alqadi, Department of Physics, Jordan University of Science and Technology, Irbid, Jordan H. M. Al-Khateeb, Department of Physics, Jordan University of Science and Technology, Irbid, Jordan N. Y. Ayoub, Department of Physics, Yarmouk University, Irbid, Jordan Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We have based on isothermal magnetization curves to study the magnetocaloric effect (MCE) in fine-grained perovskite manganites of La 0.7 Cd 0.3 MnO 3 (LCMO), La 0.7 Ba 0.3 MnO 3 (LBMO), and Nd 0.7 Sr 0.3 MnO 3 (NSMO) prepared by conventional solid-state reaction. Magnetic measurements were performed on a vibrating sample magnetometer, with a temperature increment of 1.0 K, and the applied field in the range of 0–1.8 T. Under an applied field of 1.8 T, the maximum magnetic-entropy change obtained for LCMO, LBMO, and NSMO taking place at their Curie temperature are about 2.3, 2.1, and 5.1 J/(kg⋅K), respectively. The large entropy change in NSMO makes it suitable for magnetic-cooling applications. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-011-1252-z Authors P. Zhang, BK21 Physics Program and Department of Physics, Chungbuk National University, Cheongju, 361-763 South Korea T. L. Phan, BK21 Physics Program and Department of Physics, Chungbuk National University, Cheongju, 361-763 South Korea S. C. Yu, BK21 Physics Program and Department of Physics, Chungbuk National University, Cheongju, 361-763 South Korea Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    This paper describes a novel method to increase the resistive T c of cuprate superconductors to values approaching room temperature. The method is based on our analysis of the inhomogeneous superconducting state for the “pseudogap” region and on the interplay of doping and pair-breaking phenomena. What we propose involves specific ordering of the dopants that leads to the formation of regions that can carry a supercurrent at high temperatures. Content Type Journal Article Category Letter Pages 1-3 DOI 10.1007/s10948-011-1363-6 Authors S. A. Wolf, Departments of Physics and Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904, USA V. Z. Kresin, Lawrence Berkeley National Laboratory, University of California at Berkeley, Berkeley, CA 94720, USA Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Physical properties of the Sm 1− x Tb x Ni 4 B (0≤ x ≤0.8) compounds have been investigated by means of the X-ray powder diffraction, AC-susceptibility and DC-magnetization techniques. All the compounds studied crystallize in CeCo 4 B-type structure with P6/mmm space group. The substitution of Tb for Sm leads to a decrease of the unit-cell parameters a , c and the unit-cell volume V . The magnetic phase transition temperatures are found as 39, 30, 26, 22 and 15 K, for x =0, 0.2, 0.4, 0.6 and 0.8, respectively. In addition, we have seen the second magnetic phase transition around 230 K, at the ac-susceptibility results. We have concluded that this behavior may arise from the Tb–Tb interaction in crystal structure. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10948-011-1361-8 Authors Onur Nane, Department of Electrical and Electronics Engineering, Faculty of Engineering, Hakkari University, Hakkari, Turkey Bekir Özçelik, Department of Physics, Faculty of Sciences and Letters, Cukurova University, 01330 Adana, Turkey Selçuk Kervan, Department of Physics, Faculty of Sciences and Letters, Nevşehir University, 50300 Nevşehir, Turkey Uğur Topal, TÜBİTAK-UME, National Metrology Institute, P.O. Box 54, 41470 Gebze-Kocaeli, Turkey Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Muon spin rotation ( μ SR) experiments were performed on the intercalated graphite CaC 6 in the normal and superconducting state down to 20 mK. In addition, AC magnetization measurements were carried out resulting in an anisotropic upper critical field , from which the coherence lengths ξ ab (0)=36.3(1.5) nm and ξ c (0)=4.3(7) nm were estimated. The anisotropy parameter increases monotonically with decreasing temperature. A single isotropic s -wave description of superconductivity cannot account for this behavior. From magnetic field dependent μ SR experiments, the absolute value of the in-plane magnetic penetration depth λ ab (0)=78(3) nm was determined. The temperature dependence of the superfluid density ρ s ( T ) is slightly better described by a two-gap than a single-gap model. Content Type Journal Article Category Letter Pages 1-5 DOI 10.1007/s10948-011-1358-3 Authors F. Murányi, Physik-Institut der Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland M. Bendele, Physik-Institut der Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland R. Khasanov, Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland Z. Guguchia, Physik-Institut der Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland A. Shengelaya, Department of Physics, Tbilisi State University, Chavchavadze 3, 0128 Tbilisi, Georgia C. Baines, Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland H. Keller, Physik-Institut der Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In this work, Monte Carlo simulation was used to model the dynamic hysteresis behavior of magnetic/non-magnetic multilayers in the framework of Heisenberg model using the spin-flip algorithm. The purpose is to investigate the hysteresis properties while varying the direction of external applied magnetic field and temperature taking account interface composition of magnetic/non-magnetic atoms. From the results, with thermal variation and interface composition, the simulated hysteresis loops change significantly due to the competition between magnetic anisotropy in magnetic films and the presence of isolated clusters at the interface. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1492-6 Authors A. Razouk, Laboratoire de Physique et Mécanique des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, B.P. 523, 23000 Béni Mellal, Morocco M. Sahlaoui, Laboratoire de Physique et Mécanique des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, B.P. 523, 23000 Béni Mellal, Morocco M. Sajieddine, Laboratoire de Physique et Mécanique des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, B.P. 523, 23000 Béni Mellal, Morocco Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The e-ph coupling may be of the different strength for different electronic bands. If coupling is strong enough for one or more bands, polaronic effects practically decouple these bands from the rest. Single ions being dressed by strong e-ph interactions move in the local potentials having two or more minima, and hence, can be viewed as the system of the Ising spins. Intersite interactions via the RKKY-type exchange by the electron-hole pairs tend to order the latter thus providing the CDW instability mechanism with a structural vector, Q that has nothing in common with the Fermi surfaces parameters. Among the most typical manifestations of such strong e-ph coupling in the system are large characteristic energy scales significantly exceeding the temperatures for the onset of the CDW phase. The available experimental data support interpretation of properties of the transition-atoms-dichalcogenides and the compounds of the A15 group in terms of the local polaronic effects. Content Type Journal Article Category Complex Systems Pages 1-7 DOI 10.1007/s10948-012-1448-x Authors Lev P. Gor’kov, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    This survey provides a brief account for the start of organic superconductivity motivated by the quest for high T c superconductors and its development since the 1980s. Besides superconductivity found in 1D organics in 1980, progresses in this field of research have contributed to better understand the physics of low-dimensional conductors highlighted by the wealth of new remarkable properties. Correlations conspire to govern the low-temperature properties of the metallic phase. The contribution of antiferromagnetic fluctuations to the interchain Cooper pairing proposed by the theory is borne out by experimental investigations and supports superconductivity emerging from a non-Fermi-liquid background. Quasi-one-dimensional organic superconductors can therefore be considered as simple prototype systems for the more complex high T c materials. Content Type Journal Article Category Superconductivity Pages 1-23 DOI 10.1007/s10948-012-1475-7 Authors Denis Jérome, Laboratoire de Physique des Solides, Université Paris-Sud, 91405 Orsay, France Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The possible relationship between Kondo lattices an superconductivity is discussed for the case of granular superconductors, based on the empirical evidence that they display strong correlation effects near a metal to insulator transition. Content Type Journal Article Category Complex Systems Pages 1-4 DOI 10.1007/s10948-012-1453-0 Authors Guy Deutscher, School of Physics and Astronomy, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978 Israel Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description: Jacques Friedel and Metallurgy Content Type Journal Article Category Metallurgy, Dislocations, Strains Pages 1-2 DOI 10.1007/s10948-012-1471-y Authors Georges Saada, Laboratoire D’Etude des Microstructures, Onera, 92322 Chatillon, France Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Mn 3 O 4 nanoparticles were synthesized via an ionic liquid (IL) assisted process at room temperature, which is rather difficult to achieve by other techniques. The synthesized product was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, thermal gravimetry (TG), and vibrating sample magnetometry (VSM). The prepared material showed a high purity, while crystallite size and particle size agree well with each other, 17±2 and 19±3 nm, respectively, revealing nearly single crystalline character of nanoparticles. The product contains 4 wt% of adsorbed water and ionic liquid. This method provides a facile, one-step, and low-cost route for the synthesis of nanostructures of metal oxides. In addition, [BMIM]BF 4 could be collected and reused for subsequent reactions. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1451-2 Authors Merva Günay, Department of Chemistry, Fatih University, B. Cekmece, 34500 Istanbul, Turkey Abdülhadi Baykal, Department of Chemistry, Fatih University, B. Cekmece, 34500 Istanbul, Turkey Muhammet S. Toprak, Functional Materials Division, Royal Institute of Technology, 16440 Stockholm, Sweden Hüseyin Sözeri, TUBITAK-UME, National Metrology Institute, PO Box 54, 41470 Gebze-Kocaeli, Turkey Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Screening of the Coulomb interaction accounting for the Friedel oscillations in the structures with multicomponent low-dimensional electron plasma is considered. Calculations are made for nanotubes, double quantum wells (DQW) and superlattices. We consider also screening of an impurity potential by neutral particles—indirect dipolar excitons, as well as Friedel oscillations in a hybrid electron–exciton system. Content Type Journal Article Category Nanostructures; Low dimensional systems Pages 1-11 DOI 10.1007/s10948-012-1437-0 Authors A. V. Chaplik, Institute of Semiconductor Physics, 630090 Novosibirsk, Russia V. M. Kovalev, Institute of Semiconductor Physics, 630090 Novosibirsk, Russia L. I. Magarill, Institute of Semiconductor Physics, 630090 Novosibirsk, Russia R. Z. Vitlina, Institute of Semiconductor Physics, 630090 Novosibirsk, Russia Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In this paper, a series of iron (Fe) containing nanoparticles were prepared by employing PAMAM (Poly(amidoamine), dendrimers with different generations (G0–G3) as templates and sodium borohydride as a reducing agent. The products have been characterized by TEM, FT-IR, XRD, VSM, TGA, and XPS. XRD analysis reveal low crystallinity of formed particles within the dendrimers, however, crystallinity of the nanoparticles was observed to increase with increasing generation of dendrimers. Dominant phases were determined as magnetite (Fe 3 O 4 or maghemite, γ -Fe 2 O 3 ). XPS analysis revealed the chemical composition of nanoparticles as iron oxide which indicated the oxidation of Fe species subsequent to the reduction process, in agreement with XRD analysis. The magnetization curves have superparamagnetic nonhysteretic characteristic at lower fields and with nonsaturation characteristic at high fields. Magnetic evaluation of samples with the 20:1 molar ratio of Fe:PAMAM showed decreasing superparamagnetic character and decreasing saturation magnetisation with increasing generation of dendrimers. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10948-012-1454-z Authors A. Baykal, Department of Chemistry, Fatih University, B. Cekmece, 34500 Istanbul, Turkey M. S. Toprak, Functional Materials Division, Royal Institute of Technology—KTH, 16440 Stockholm, Sweden Z. Durmus, Department of Chemistry, Fatih University, B. Cekmece, 34500 Istanbul, Turkey M. Senel, Department of Chemistry, Fatih University, B. Cekmece, 34500 Istanbul, Turkey H. Sozeri, TUBITAK-UME, National Metrology Institute, PO Box 54, Gebze, 41700 Kocaeli, Turkey A. Demir, Department of Chemistry, Fatih University, B. Cekmece, 34500 Istanbul, Turkey Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In this study, superconducting samples of type Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10− δ added by SnO 2 and In 2 O 3 in nano-scale were prepared by a solid-state reaction technique. The concentrations of both SnO 2 and In 2 O 3 were 0.0, 0.1, 0.2, 0.4, 0.6 and 1.0 wt% of the sample’s total mass. The prepared samples were characterized using X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) for phase analysis and microstructure examination. The elemental content of the prepared samples was determined using energy dispersive X-ray (EDX) and particle induced X-ray emission (PIXE). The results of elemental content, determined from EDX and PIXE, were compared and discussed. In addition, The oxygen content of these samples was obtained using non Rutherford backscattering spectroscopy (RBS) at 3 MeV proton beam. It was found that the Oxygen-content of (Cu 0.5 Tl 0.5 )-1223 phase was not affected by both SnO 2 and In 2 O 3 nano-oxides addition. The electrical resistivity of the prepared samples was measured by the conventional four-probe technique from room temperature down to the zero superconducting transition temperature ( T 0 ). An increase in the superconducting transition temperature T c from 106 to 119 K was observed as x was varied from 0.0 to 0.6 wt% for (SnO 2 ) x Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10− δ , followed by a systematic decrease with increasing nano-SnO 2 addition. On the other hand, the T c values for (In 2 O 3 ) x Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3 O 10− δ show a small variation with  x . Moreover, the variation rate of T c with x , for both nano-additions, was found to be directly proportional to the variation of the volume fraction of the prepared samples. Content Type Journal Article Category Original Paper Pages 1-14 DOI 10.1007/s10948-012-1465-9 Authors N. H. Mohammed, Physics Department, Faculty of Science, Alexandria University, Moharam Bek, P.O. Box, 21511 Alexandria, Egypt R. Awad, Physics Department, Faculty of Science, Alexandria University, Moharam Bek, P.O. Box, 21511 Alexandria, Egypt A. I. Abou-Aly, Physics Department, Faculty of Science, Alexandria University, Moharam Bek, P.O. Box, 21511 Alexandria, Egypt I. H. Ibrahim, Physics Department, Faculty of Science, Alexandria University, Moharam Bek, P.O. Box, 21511 Alexandria, Egypt M. Roumié, Accelerator Laboratory, Lebanese Atomic Energy Commission, National Council for Scientific Research, Airport Road, P.O. Box 11, 8281 Beirut, Lebanon M. Rekaby, Physics Department, Faculty of Science, Alexandria University, Moharam Bek, P.O. Box, 21511 Alexandria, Egypt Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Electronic structures of ZnO-based dilute magnetic semiconductors (DMS) are investigated within the self-interaction-corrected local density approximation (SIC-LDA). These results are compared with those calculated within the standard LDA. The Korringa–Kohn–Rostoker method combined with coherent potential approximation has been used. We find the differences between LDA and SIC-LDA calculations, in the band-gap energy. The energetic position of the Zn 3d bands and the description of the transition-metal d bands, have been studied. In contrast to the standard LDA calculations, the results obtained within SIC-LDA are in good agreement with the experimental ones. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10948-012-1470-z Authors E. Salmani, LMPHE (URAC 12), Departement de Physique, Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco A. Benyoussef, LMPHE (URAC 12), Departement de Physique, Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco H. Ez-Zahraouy, LMPHE (URAC 12), Departement de Physique, Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco E. H. Saidi, LPHE, Departement de Physique, Faculté des Sciences, Université Mohammed V-Agdal, Rabat, Morocco Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Optical and photocatalytic properties of ZnS, ZnS:Mn 2+ (20 and 30 wt%) and ZnS:Sm 3+ (20 and 30 wt%) samples formed by three coatings, were studied. The layers were deposited on glass substrate by the sol-gel dip coating process. The catalytic activity of the samples was determined by means of the photodecomposition of methylene blue under Ultra Violet and visible light irradiations. The Fourier Transform Infrared (FTIR) spectrum of ZnS shows the presence of OH, N–H, N–C and S–H groups. The last two groups suggest the formation of a thiocyanuric group (NCS − ) on the surface of the sample which enables the photocatalytic activity of undoped ZnS and doped ZnS under visible light irradiation. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1432-5 Authors E. Gómez-Barojas, CIDS-IC, Benemérita Universidad Autónoma de Puebla, Puebla, Pue 72570, Mexico E. Sánchez-Mora, Instituto de Física, BUAP. Apdo, Postal J-48, Puebla, Pue 72570, Mexico C. Castillo-Abriz, Instituto de Física, BUAP. Apdo, Postal J-48, Puebla, Pue 72570, Mexico E. Flores-Rodríguez, Instituto de Física, BUAP. Apdo, Postal J-48, Puebla, Pue 72570, Mexico R. Silva-González, Instituto de Física, BUAP. Apdo, Postal J-48, Puebla, Pue 72570, Mexico Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    An off-equilibrium redox condition study of Mn 2+ and Mn 4+ ions added to the batch is reported for the case of the preparation of the barium aluminoborate glasses, by considering that the out of equilibrium reactions started already on the melt. It is shown that for lower dopant concentrations the relative concentrations of the oxidation states of the manganese are found out of equilibrium up to the added amount of 0.3 mol% of MnO 2 , but on doping with MnO, the equilibrium state is achieved at the MnO added amount of 0.07 mol%. The change of the redox condition of the manganese ions toward the equilibrium was studied by tracking the Mn 2+ amount as a function of the doping concentration in the two cases of MnO and MnO 2 . Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1457-9 Authors J. M. Giehl, Institute of Physics Gleb Wataghin, University of Campinas, Campinas, SP, Brazil A. R. Miranda, Institute of Physics Gleb Wataghin, University of Campinas, Campinas, SP, Brazil W. M. Pontuschka, Institute of Physics, University of São Paulo, São Paulo, SP, Brazil M. Navarro, Institute of Physics, University of São Paulo, São Paulo, SP, Brazil Z. M. Da Costa, Institute of Exact Science, Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In this work, we report synthesis and characterization of the new La 2 SrCo 2 FeO 9 triple perovskite material. The samples were produced by the solid-state reaction method. The analyses of the XRD patterns were made by Rietveld refinement through the GSAS code. The results reveal that the material crystallizes in an orthorhombic complex perovskite, space group Immm (#71) with lattice parameters a =5.4314(3) Ǻ, b =5.4583(3) Ǻ and c =7.7018(2) Ǻ. SEM micrographs evidence a strongly diffused granular morphology with mean grain size of 2 μm and the EDX spectra show that the chemical composition of samples are in good agreement with the nominal values of the stoichiometric formula. 57 Fe Mössbauer spectroscopy recorded at 300 K reveals two sites in concordance with the X-ray diffraction measurements, and its valence state is +3, as determined from the isomer shift found. At 4.2 K magnetic ordering with canting of the Fe moments is found. Measurements of the magnetization as a function of temperature permitted us to determine the ferromagnetic characteristic of material with an effective magnetic moment of 9.7 μ B . Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1425-4 Authors Julio C. Albornoz, Grupo de Física de Nuevos Materiales, Departamento de Física, Universidad Nacional de Colombia, AA 5997 Bogotá DC, Colombia David A. Landínez Téllez, Grupo de Física de Nuevos Materiales, Departamento de Física, Universidad Nacional de Colombia, AA 5997 Bogotá DC, Colombia Jairo Roa-Rojas, Grupo de Física de Nuevos Materiales, Departamento de Física, Universidad Nacional de Colombia, AA 5997 Bogotá DC, Colombia Julian A. Munévar, Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro, RJ, Brasil Elisa Baggio-Saitovich, Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro, RJ, Brasil Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In the present paper, the effect of non-polar longitudinal optical phonons on domain wall resistance has been studied using the semiclassical approach. The analysis has been based on the Boltzmann transport equation, within the relaxation time approximation. We have determined the magnetoresistance of domain wall in nanowires based on diluted magnetic semiconductors. The modulation of the exchange and the impurity interactions by lattice vibrations, and the hole–phonon interaction are considered. The results indicate that the scattering role of phonons becomes significant by increasing temperature, which leads to the resistivity enhancement. It is also found that the magnetic impurities play an impressive role in enhancing the contribution of the domain wall in the resistance. In providing room temperature spintronics devices, understanding the effects of phonons and magnetic impurities on the domain wall resistance is crucial. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1487-3 Authors R. Majidi, Department of Physics, Shahid Rajaee Teacher Training University, 16788-15811 Tehran, Iran M. M. Tehranchi, Department of Physics, Shahid Beheshti University, G.C., Evin, 19839-63113 Tehran, Iran A. Phirouznia, Department of Physics, Azarbaijan University of Tarbiat Moallem, 53714-161 Tabriz, Iran Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Thick films of ((Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O x ) 1− y (La 0.7 Sr 0.3 MnO 3 ) y [(Bi2223) 1− y (LSMO) y ] composites ( y =0.01, 0.03, 0.05) are deposited by means of a simple melting-quenching-annealing method onto (001)-oriented LaAlO 3 (LAO) substrates. The constituent compounds Bi2223 and LSMO are prepared by standard solid-state reaction and sol–gel method, respectively. Measurements of the dependence of the magnetization on the temperature show the presence of superconducting and ferromagnetic phase below ∼54 K and ∼370 K, respectively. Current–voltage measurements on composites with y =0.01, 0.03 show that the superconducting critical current drop dramatically from I c ≈350 mA at T =15 K to zero at T ≈0.5 T c (∼25 K). The dependence of the magnetization on the external magnetic field applied in-plane or out-of-plane at 5 K displays well defined hysteresis loops, which correspond to the superconducting, diamagnetic phase. For T 〉 T c , the ferromagnetic loop of LSMO is observed. The critical current density, J c , was determined for samples with y =0.01 and 0.05 by applying Kim’s model to the superconducting, diamagnetic hysteresis recorded at 5 K. The calculated values for J c ( B ) resulted to be smaller than those obtained for individual bulk Bi2223 samples due, probably, to the presence of LSMO particles whose ferromagnetic domains compete with the superconducting diamagnetic phase. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1455-y Authors O. Paredes, Centro de Materiales, Facultad de Ingeniería, Universidad de Nariño, Ciudad Universitaria Torobajo, Pasto, Colombia E. Baca, Grupo de Ingeniería de Nuevos Materiales, Departamento de Física, Universidad del Valle, A.A. 25360 Cali, Colombia O. Morán, Laboratorio de Materiales Cerámicos y Vítreos, Departamento de Física, Universidad Nacional de Colombia, Sede Medellín, A.A. 568, Medellín, Colombia Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The interaction between a cylindrical magnet and a superconducting hollow cylinder in the Meissner state was analyzed using a dipole–dipole model. Analytical expression of the levitation force was derived as a function of the magnetic moment, radius of the magnet, radius, and thickness of the superconductor sample. The effect of the magnet’s dimensions on the levitation force was studied. The obtained results show that there is strong dependence of the levitation force on the magnetic dipole orientation at a small magnet–superconductor distance. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1483-7 Authors M. K. Alqadi, Department of Physics, Jordan University of Science and Technology, Irbid, Jordan F. Y. Alzoubi, Department of Physics, Jordan University of Science and Technology, Irbid, Jordan S. M. Saadeh, Department of Physics, Jordan University of Science and Technology, Irbid, Jordan H. M. Al-Khateeb, Department of Physics, Jordan University of Science and Technology, Irbid, Jordan N. Y. Ayoub, Dean of Graduate Studies, German Jordanian University, Amman, Jordan Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The first-principles full potential linearized augmented plane wave method within spin-polarized density functional theory was used to investigate the structural, electronic, and magnetic properties of NaX compounds in the NiAs, rocksalt (RS), and zincblende (ZB) phases. The results showed that in all compounds, the stable state phase is a nonmagnetic (NM) NiAs structure except for NaO in which the stable state phase is a ferromagnetic (FM) RS structure. The ZB NaX (X=O, S, Se, Te, and Po) and RS NaX (X=O, S, and Se) structures are half-metallic (HM) ferromagnets with an integer magnetic moment of 1 μ B per formula unit. The half-metallicity originates from hybridization between X p and Na s and p states. The ZB NaO compound is a very robust half-metal which has the HM band gap of 1.25 eV and maintains HM characteristic up to above 40% of the lattice constant contraction. The half-metallicity is also found up to the lattice constant contraction of about 26.3%, 19.6%, 10.4%, and 7.5% for ZB NaS, NaSe, NaTe, and NaPo and 27.1%, 6.4%, and 1.7% for RS NaO, NaS, and NaSe, respectively. The robustness of half-metallicity with respect to the lattice contraction in the HM NaX compounds and their compatibility with the binary semiconductors make them suitable candidates in spintronic applications. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10948-012-1480-x Authors F. Ahmadian, Department of Physics, Shahreza Branch, Islamic Azad University, Shahreza, Iran Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In order to check the solubility of Zn in the (Sr 1− x Zn x )CoO 3 perovskite structure and their research findings, several polycrystalline samples have been prepared under wide extreme synthesis conditions at 6 GPa/1300–1650 °C. While 0.05≤ x ≤0.3 compositions revealed single phased cubic structure materials, x 〉0.3 showed multi-phased materials for (Sr 1− x Zn x )CoO 3 system. Like other substituted perovskite cobalt oxide systems (Ca, Y, Ho and Ce), the transport properties of the present materials show rather sizable changes with respect to ‘ x ’, although there are insignificant variations in lattice parameter and in Curie temperature, T c . All the present samples show soft ferromagnetism with T c in the range of 272–285 K for 0.05≤ x ≤0.3. The effective paramagnetic moment, P eff determined from the paramagnetic region decreases upon the substitution of Zn for Sr-site. These P eff (3.3–2.8 μ B /Co) values for 0.05≤ x ≤0.3 compositions seem to suggest that the Co 4+ lie in intermediate spin (IS) state for the present (Sr 1− x Zn x )CoO 3 series, although they are slightly smaller than those expected for IS-Co 4+ ; P eff =3.87 μ B /Co. The electrical resistivity is found to increase with increase of ‘ x ’ for the investigated samples. The temperature and field dependence of both positive and negative magnetoresistance (MR) are noted for the Zn substituted samples. About 5% of –MR is observed for x =0.05 sample around the transition temperature (280 K) under the field strength difference, Δ H =90 kOe. The present research findings are compared with our previous results on different perovskite cobalt oxides. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10948-012-1488-2 Authors S. Balamurugan, Advanced Nanomaterials Research Laboratory, Department of Nanotechnology, Noorul Islam Centre for Higher Education, Kumaracoil, Thuckalay, 629 180 Tamilnadu, India Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The determination of their critical current density in the whole range of the temperature below T c is of first importance to understand the physical processes occurring in superconducting films. We describe here a technique suitable for square films based on the measurement of the magnetic moment due to the currents persisting in the superconductor after the application of a perpendicular high magnetic field. Typically, with a SQUID magnetometer, the measurement time in the whole range of temperature with a 1 K interval is of 2 hours only by this technique. An intriguing aspect of the obtained results is that they are much more accurate if the current lines are supposed to be circular than if we suppose, as suggested by theoretical considerations and magnetooptical observations that they have the sample symmetry. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1782-z Authors Conor McLoughlin, CRISMAT-ENSICAEN, UMR-CNRS 6508, 14050 Caen, France Pierre Bernstein, CRISMAT-ENSICAEN, UMR-CNRS 6508, 14050 Caen, France Yohann Thimont, CRISMAT-ENSICAEN, UMR-CNRS 6508, 14050 Caen, France J. Siejka, INSP, UMR-CNRS 7588, 75251 Paris, France Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Isothermal magnetization data in the critical region of the ferromagnetic transition for Co-doped SnO 2 -based diluted magnetic semiconductor were measured and analyzed in terms of the modified Arrott plot method and, independently by the Kouvel–Fisher method. The critical exponents β , γ , and δ , corresponding to spontaneous magnetization, initial susceptibility and isothermal magnetization, respectively, were determined and the values are found to be comparable to the mean-field model. The critical exponent values are found to be consistent with the Widom scaling relation and the universal scaling hypothesis. The temperature variation of the effective critical exponent is found to show the characteristic behavior of a disordered system. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10948-012-1697-8 Authors Sunita Mohanty, Department of Physics, Indian Institute of Technology Guwahati, Guwahati, 781039 India S. Ravi, Department of Physics, Indian Institute of Technology Guwahati, Guwahati, 781039 India Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Multiferroic BiFeO 3 and Cr-doped (0.90)BiFe 1− x Cr x O 3 –(0.10)BaTiO 3 ( x =0.00, 0.03, and 0.05) nanocomposites were prepared by sol–gel method. Optimum calcination and sintering strategies for obtaining pure perovskite phase have been determined. X-ray diffraction and transmission electron microscope (TEM) were used for the structural and particle size analysis, whereas LCR and SQUID magnetometer was used for dielectric and magnetic measurements. TEM measurements show that the average particle sizes of all the samples were ∼19 nm. The dielectric constant was found to be increased twofold in low frequency region with the Cr-doping for x =0.05 in (0.90)BiFe 1− x Cr x O 3 –(0.10)BaTiO 3 . The hysteresis curve ( M – H ) exhibits ferromagnetic nature for all the samples ( x =0.0, 0.03, and 0.05) and the spontaneous magnetization at room temperature was found to be 0.63 emu/gm in pure BiFeO 3 , which increased to 0.99 emu/gm for x =0.05. Zero-field-cooled (ZFC) and field-cooled (FC) magnetization curves show large discrepancy suggesting spin glass behavior. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10948-012-1736-5 Authors Mohit Sahni, Department of Physics, Motilal Nehru National Institute of Technology, Allahabad, India Sushant Singh, Department of Physics, Motilal Nehru National Institute of Technology, Allahabad, India Richa Bhargava, Department of Physics, Motilal Nehru National Institute of Technology, Allahabad, India Amit Kumar Chawla, Institute Instrumentation Centre, IIT Roorkee, Roorkee, India Ramesh Chandra, Institute Instrumentation Centre, IIT Roorkee, Roorkee, India Anshuman Dalvi, Department of Physics, BITS, Pilani, India Neha Gupta, Department of Physics, BITS, Pilani, India Sanjeev Kumar, Dharmsinh Desai University, Gujarat, India Naresh Kumar, Department of Physics, Motilal Nehru National Institute of Technology, Allahabad, India Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Temperature-dependent magnetic flux density ( B ) data, clearly exhibiting a transition temperature called intrinsic blocking temperature for some metallic samples in zero field cooled-warmed (ZFC-W) curves without employing an external magnetic field, has been obtained by a simple method. The reasons of the increase and decrease in the measured B -field at low temperature in zero magnetic-field were discussed. Co, CoPt 3 and Co/Au, CoPt 3 /Au core-shell nanoparticles, prepared by the reverse-micelle microemulsion method, were used as test materials. The blocking temperature was measured at a cusp of the measured magnetic field, B (produced by the sample), versus the temperature curve during warming up of the sample from a very low temperature (≤15 K) to room temperature. All the samples showed a blocking temperature at 45, 50, 40, and 42 K, respectively, for Co, CoPt 3 , Co/Au, and CoPt 3 /Au nanoparticles. A completely intrinsic behavior of the sample’s magnetic moment was revealed by our method since no applied external field was used, yielding a truly spontaneous magnetization behavior. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10948-012-1742-7 Authors Ghazaleh Bahmanrokh, Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia Mansor Hashim, Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia Ismayadi Ismail, Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia Nayereh Soltani, Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia Parisa Vaziri, Department of Medical Physics and Biomedical Engineering, Shahid Beheshti University of Medical Sciences, Velenjak, Daneshju Blvd., Tehran, 1983963113 Iran Mohd Shamsul Ezzad Shafie, Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia Manizheh Navaseri, Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    A systematic investigation was done to determine the structural, morphological and magnetic properties of Zn 0.8 Co 0.2 O nanoparticles synthesized by a simple autocombustion technique. XRD, FE-SEM and EDX measurements were implemented for the structural, morphological and compositional investigation of the product. Additionally VSM was used for the magnetic property investigations of the sample. The average particle size of the nanoparticles was estimated using Debye–Scherrer’s equation and found to be 20.8 nm. Magnetization measurements have shown that the particles have room-temperature ferromagnetic behavior with relatively high coercive fields. Magnetization and the coercive field of the sample increase by decreasing the temperature, as expected. FMR signal confirms the room-temperature enhanced ferromagnetic behavior without Co precipitates. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1772-1 Authors Yüksel Köseoğlu, Department of Physics, Fatih University, Buyukcekmece, 34500 Istanbul, Turkey Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We have examined theoretically the electronic band structure and Fermi surface (FS) of the tetragonal low-temperature superconductor Bi 2 Pd. Our main results are that (i) the Pd 4 d and Bi 6 p states determine the main peculiarities of the multiple-sheet FS topology, thus for this material a complicated superconducting gap structure with different energy gaps on different FS sheets should be assumed; (ii) the effect of spin-orbit coupling is of minor importance for the distributions of the near-Fermi electronic states; and (iii) this phase adopts a 3D-like type owing to directional bonds between the adjacent atomic sheets. Content Type Journal Article Category Letter Pages 1-4 DOI 10.1007/s10948-012-1776-x Authors I. R. Shein, Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg, Russia A. L. Ivanovskii, Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg, Russia Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The effect of electrolyte pH on structural, magnetic, and magnetoresistive properties of Co–Ni films was studied. The films were deposited on a titanium substrate from the electrolytes with 4.10±0.05, 3.14±0.05, and 2.14±0.05 pH values. The Co–Ni system exhibited anomalous codeposition. Structural analysis indicated that the films had (220) preferential oriented face-centered cubic structure and their surface became smoother as the electrolyte pH decreased. The compositional and magnetic analysis revealed that an increase of the Co content in the films resulted in an increase in saturation magnetization and coercivity. Magnetoresistance curves indicated that the films show anisotropic magnetoresistance. Longitudinal and transversal magnetoresistances were found to be the highest values of 8 % and 7 %, respectively, for the film deposited at a low electrolyte pH. The variation of the Co:Ni ratio in deposits caused by the change of the electrolyte pH has a considerable effect on the properties of the films. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1774-z Authors Ali Karpuz, Physics Department, Kamil Ozdag Science Faculty, Karamanoglu Mehmetbey University, Karaman, Turkey Hakan Kockar, Physics Department, Science & Literature Faculty, Balikesir University, Balikesir, Turkey Mursel Alper, Physics Department, Science & Literature Faculty, Uludag University, Bursa, Turkey Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Based on a tight-binding model and a generalized Green’s function method in the Landauer−Büttiker formalism, the current-voltage characteristics, the noise power resulting of the spin-dependent current fluctuations and Fano factor of poly(G)-poly(C) DNA molecule sandwiched between ferromagnetic three-dimensional electrodes (FM/DNA/FM) are numerically investigated. It is found when the bias voltage increased, the current and noise power increase and the Fano factor decreases. Our results show the spin-dependent transport properties are significantly influenced by the electrode/molecule coupling strength so that the reinforcement of the electrode/molecule coupling strength give rise to increasing of the current and noise power so that the Fano factor decreased. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10948-012-1768-x Authors A. Ahmadi Fouladi, Department of Physics, Sari Branch, Islamic Azad University, Sari, Iran S. A. Ketabi, School of Physics, Damghan University, Damghan, Iran Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The present study is focused on the copper-doped ZnO system. Bulk copper-doped ZnO pellets were synthesized by a solid-state reaction technique and used as target material in pulsed laser deposition. Thin films were grown for different Cu doped pellets on sapphire substrates in vacuum (5×10 −5  mbar). Thin films having (002) plane of ZnO showed different oxidation states of dopants. M – H curves exhibited weak ferromagnetic signal for 1–3 % Cu doping but for 5 % Cu doped thin film sample showed the diamagnetic behavior. For deeper information, thin films were grown for 5 % Cu doped ZnO bulk pellet in different oxygen ambient pressures and analyzed. PL measurement at low temperature showed the emission peak in thin films samples due to acceptor-related transitions. XPS results show that copper exists in Cu 2+ and Cu +1 valence states in thin films and with increasing O 2 ambient pressure the valence-band maximum in films shifts towards higher binding energy. Furthermore, in lower oxygen ambient pressure (1×10 −2  mbar) thin films showed magnetic behavior but this vanished for the film grown at higher ambient pressures of oxygen (6×10 −2  mbar), which hints towards the decrease in donor defects. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10948-012-1710-2 Authors S. Karamat, Natural Science and Science Education, National Institute of Education, Nanyang Technological University, Singapore, 637616 Singapore R. S. Rawat, Natural Science and Science Education, National Institute of Education, Nanyang Technological University, Singapore, 637616 Singapore T. L. Tan, Natural Science and Science Education, National Institute of Education, Nanyang Technological University, Singapore, 637616 Singapore P. Lee, Natural Science and Science Education, National Institute of Education, Nanyang Technological University, Singapore, 637616 Singapore S. V. Springham, Natural Science and Science Education, National Institute of Education, Nanyang Technological University, Singapore, 637616 Singapore Anis-ur-Rehman, Department of Physics, COMSATS Institute of Information Technology, 22060 Islamabad, Pakistan R. Chen, Division of Physics and Applied Physics, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371 Singapore H. D. Sun, Division of Physics and Applied Physics, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371 Singapore Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Spray pyrolysis was used to deposit MgO films on polycrystalline 321-austentic stainless steel substrates using magnesium nitrates and magnesium acetates as precursors. The MgO films deposited from the nitrate precursors were amorphous; however, MgO (200) oriented films were obtained when the acetates precursors were used. The texture of the films was improved with increasing the concentration and the deposition temperature. To evaluate the performance of the MgO buffers, PLD was used to deposit YBCO on MgO-buffered 321 substrates. Only the smoothest MgO films were found as good buffers for the deposition of c -axis oriented YBCO films. The superconducting transition temperature was broad and the T C onset was 83.6 K. Austenitic 321 steel is an alternative for C276 as a substrate for thin film deposition. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10948-012-1740-9 Authors Shadi Al-Khateeb, Department of Materials Engineering, Al-Balqa’ Applied University, Al-Salt, 19117 Jordan D. Pavlopoulos, School of Metallurgy and Materials, University of Birmingham, Birmingham, B15 2TT UK T. W. Button, School of Metallurgy and Materials, University of Birmingham, Birmingham, B15 2TT UK J. S. Abell, School of Metallurgy and Materials, University of Birmingham, Birmingham, B15 2TT UK Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Coherent passage of Cooper pairs in a Josephson junction (JJ) above the liquid nitrogen temperature has been the first impressive revolutionary effect induced by high critical temperature superconductors (HTS) in the domain of the study of Josephson effect (JE). But this has been only the start. A  d -wave order parameter has lead to significant novel insights in the physics of the JE turning into a device the notion of a π -junction. Spontaneous currents in a frustrated geometry, Andreev bound states, long-range proximity effect have rapidly become standard terms in the study of the JE, standing as a reference bench for conventional systems based on low critical temperature superconductors (LTS) and inspiring analogies for junctions based on novel superconductors discovered in the meantime. The extreme richness of the physics of HTS JJs has not been adequately supported by the expected impact in the applications, the main reason lying in the complexity of these materials and in the consequent unsatisfactory yield and reproducibility of the performances of the JJs within the required limits. The continuous progress in material science, and specifically in the realization of oxide multi-layers, and in nanotechnologies applied to superconductors, accompanied by the advances in a better understanding of the properties of HTS and of HTS devices, has as a matter of fact opened possible novel scenarios and interest in the field. We intend to give a brief overview on interesting new problems concerning HTS JJs of inspiration also for other systems. We also review some ideas and experimental techniques on macroscopic quantum decay phenomena occurring in Josephson structures. The attention is mainly addressed to intermediate levels of dissipation, which characterize a large majority of low critical current Josephson devices and are therefore an unavoidable consequence of nanotechnology applied more and more to Josephson devices. Content Type Journal Article Category Review Article Pages 1-21 DOI 10.1007/s10948-012-1773-0 Authors Francesco Tafuri, Dip. di Ingegneria dell’Informazione, Seconda Università degli Studi di Napoli, via Roma 29, 81031 Aversa (Ce), Italy Davide Massarotti, CNR-SPIN, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy Luca Galletti, CNR-SPIN, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy Daniela Stornaiuolo, CNR-SPIN, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy Domenico Montemurro, NEST-Scuola Normale Superiore and Istituto Nanoscienze–CNR, Piazza San Silvestro 12, 56127 Pisa, Italy Luigi Longobardi, Dip. di Ingegneria dell’Informazione, Seconda Università degli Studi di Napoli, via Roma 29, 81031 Aversa (Ce), Italy Procolo Lucignano, Dip. Scienze Fisiche, Università di Napoli Federico II, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy Giacomo Rotoli, Dip. di Ingegneria dell’Informazione, Seconda Università degli Studi di Napoli, via Roma 29, 81031 Aversa (Ce), Italy Giovanni Piero Pepe, CNR-SPIN, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy Arturo Tagliacozzo, CNR-SPIN, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy Floriana Lombardi, Dept. of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Göteborg, Sweden Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Nanosized strontium hexaferrite (SrFe 12 O 19 ) has been synthesized by citrate, urea, oxalic, and glycine precursor via a sol-gel route with poly(methyl methacrylate) (PMMA) as a templating agent. Crystal structure, morphology, and magnetic properties of as-synthesized nanoparticles were characterized by XRD, SEM, FT-IR, and VSM techniques. The formation of strontium hexaferrite and its crystallite size in presence of different fuels were compared. The influence of different fuels was reflected on the phase purity, morphology of the final powders as well as the magnetic properties. Magnetic measurements revealed that samples prepared by citric acid and glycine as fuel have high specific saturation magnetization and moderate coercivity, while urea and oxalic acid fuels resulted in low phase purity, and thus inferior magnetic properties. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10948-012-1538-9 Authors Z. Durmus, Department of Chemistry, Fatih University, B. Cekmece, Istanbul, 34500 Turkey H. Sozeri, TUBITAK-UME, National Metrology Institute, PO Box 54, Gebze, Kocaeli 41700, Turkey M. S. Toprak, Functional Materials Division, KTH Royal Institute of Technology, 16440 Stockholm, Sweden A. Baykal, Department of Chemistry, Fatih University, B. Cekmece, Istanbul, 34500 Turkey Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    SmCo 5 is an emerging perpendicular magnetic material for super-high density magnetic recording, due to its large magnetic anisotropy energy. In this paper, the magnetic moments of SmCo 5− x Cu x have been studied using first principles calculation based on density-functional theory (DFT). Calculations are performed using the pseudopotential plane wave DFT code Vienna ab initio simulation package (VASP) with the projector augmented wave (PAW) method. The local density approximation LDA+ U method is used for the calculation of the exchange correlation energy of Sm. The calculation results show that the average Co magnetic moment of SmCo 5− x Cu x decreases with the increase of Cu doping concentrations, and the influence of the Cu doping on the spin state of Co is greater than that of Sm. The magnetic anisotropy energy of SmCo 5 is analyzed. The electronic density of states and the differential in spin densities of atoms show that the spatial distribution of 4 f electron and the 4 f –3 d coupling are the controlling factors of the magnetic anisotropy energy of SmCo 5 . Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1530-4 Authors Weiming Cheng, Wuhan National Laboratory for Optoelectronics, Wuhan, 430074 China Sihai Zhao, Wuhan National Laboratory for Optoelectronics, Wuhan, 430074 China Xiaoming Cheng, Wuhan National Laboratory for Optoelectronics, Wuhan, 430074 China Xiangshui Miao, Wuhan National Laboratory for Optoelectronics, Wuhan, 430074 China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Cu 0.5 Mg 0.5 Fe 2 O 4 precursor was synthesized by solid-state reaction at low heat using CuSO 4 ⋅5H 2 O, MgSO 4 ⋅6H 2 O, FeSO 4 ⋅7H 2 O, and Na 2 C 2 O 4 as raw materials. The spinel Cu 0.5 Mg 0.5 Fe 2 O 4 was obtained via calcining precursor above 300 °C in air. The precursor and its calcined products were characterized by thermogravimetry and differential scanning calorimetry (TG/DSC), Fourier transform FT-IR, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), and vibrating sample magnetometer (VSM). The result showed that Cu 0.5 Mg 0.5 Fe 2 O 4 obtained at 600 °C had a saturation magnetization of 36.8 emu g −1 . The thermal process of Cu 0.5 Mg 0.5 Fe 2 O 4 precursor experienced two steps, which involved the dehydration of the five and a half crystal water molecules at first, and then decomposition of Cu 0.5 Mg 0.5 Fe 2 (C 2 O 4 ) 3 into crystalline Cu 0.5 Mg 0.5 Fe 2 O 4 in air. Based on the Kissinger equation, the values of the activation energy associated with the thermal process of the precursor were determined to be 85 and 152 kJ mol −1 for the first and second thermal process steps, respectively. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10948-012-1545-x Authors Jinwen Huang, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004 P.R. China Peng Su, Guangxi Institute of Metallurgy, Nanning, 530023 P.R. China Wenwei Wu, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004 P.R. China Yongni Li, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004 P.R. China Xuehang Wu, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004 P.R. China Sen Liao, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004 P.R. China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We numerically investigate the superconductor matter of a film type-II superconductor with circular geometry numerically in a computational simulation using the link variable method to solve the time dependent Ginzburg–Landau equation. We apply the implemented algorithm to a half circular film surrounded by a thin layer of another superconductor at a higher critical temperature. The film is immersed in an external magnetic field applied perpendicularly to its plane. The boundary condition is taken into account with the de Gennes extrapolation length  b . We calculate the magnetization, vortex number, the third critical thermodynamical field as a function of the external magnetic field, and the b parameter. We find that for these interfaces the third critical field and the magnetization M are largely increased. Content Type Journal Article Category Original Paper Pages 1-3 DOI 10.1007/s10948-012-1534-0 Authors J. Barba-Ortega, Departamento de Física, Universidad Nacional de Colombia, Bogotá, Colombia Miryam R. Joya, Departamento de Física, Universidad Nacional de Colombia, Bogotá, Colombia J. Albino Aguiar, Departamento de Física, Universidade Federal de Pernambuco, Recife, Brazil Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We carry out a theoretical study of the bilayer single-band Hubbard model in the undoped and in the superconducting phases by means of the variational cluster approach. In particular, we focus on the splitting between the “bonding” and “antibonding” bands induced by the interlayer hopping, as well as its interplay with strong correlation effects. We find that the splitting is considerably suppressed in both the normal and superconducting phases, in qualitative agreement with experiments on Bi 2 Sr 2 CaCu 2 O 8+ δ . In addition, in the superconducting phase, the shape of the splitting in k space is modified by correlations. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10948-012-1537-x Authors Anna M. Fulterer, Institute of Theoretical and Computational Physics TU Graz, 8010 Graz, Austria Enrico Arrigoni, Institute of Theoretical and Computational Physics TU Graz, 8010 Graz, Austria Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Niobium and tantalum sheets were loaded with tritium and their superconducting properties were investigated. Superconductivity is rather robust in both materials though they belong to different types of superconductors. The critical temperature does not change in the case of Nb at low field but decreases slightly in the case of Ta. The tritium-loaded Nb shows a higher remanent magnetization which we attribute to the subsurface accumulation of defects, but the high field irreversible magnetization is smaller than for the bare sample. In the case of Ta, both the remanent magnetization and the irreversible magnetization are slightly reduced after tritiation. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10948-012-1551-z Authors V. Sandu, National Institute of Materials Physics, Magurele, 077125 Romania S. Popa, National Institute of Materials Physics, Magurele, 077125 Romania M. S. Nicolescu, National Institute of Materials Physics, Magurele, 077125 Romania M. Enachescu, Horia Hulubei National Institute for Nuclear Physics and Engineering, Magurele, 077125 Romania E. Sandu, Horia Hulubei National Institute for Nuclear Physics and Engineering, Magurele, 077125 Romania Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    [Fe(35 Å)/Sn(45 Å)] 60 multilayer film have been prepared by a vacuum evaporation method, followed by an annealing treatment in vacuum at different temperatures going until 641 K for 3 h. This multilayer has been studied by 57 Fe Mössbauer spectrometry at room temperature; it shows that we have formation of defined compound FeSn with thickness 11 Å at the interface between the temperatures 588 and 641 K. For the temperature below 598 K, we noticed an increase in the proportion and composition of the nonmagnetic amorphous alloy when the annealing temperature increases. Mössbauer spectroscopy also shows that the Fe in the multilayer is in a α -Fe state. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1520-6 Authors S. El Khiraoui, Laboratoire de Physique et Mécaniques des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, BP 523, 23000 Béni-Mellal, Maroc M. Sajieddine, Laboratoire de Physique et Mécaniques des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, BP 523, 23000 Béni-Mellal, Maroc Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The in-plane magnetoresistance (MR) of a single crystal La 1.97 Sr 0.03 CuO 4 has been studied at low temperatures T using several experimental protocols. At T well below the spin-glass transition temperature, the MR becomes positive and exhibits several glassy features, such as history dependence, memory, and hysteresis. These observations are qualitatively similar to the previously reported behavior of the out-of-plane resistance. The results suggest that the memory effects in the MR are related to the onset of glassiness in the dynamics of doped holes. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1542-0 Authors I. Raičević, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA Dragana Popović, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA C. Panagopoulos, Division of Physics and Applied Physics, Nanyang Technological University, Singapore, Singapore T. Sasagawa, Materials and Structures Laboratory, Tokyo Institute of Technology, Kanagawa, Japan Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The design and fabrication of the model coil for the 40 T hybrid superconducting outsert has been completed at High Magnetic Field Laboratory, Chinese Academy of Sciences (CHMFL). “Wind-and-React” method is adopted to ease subsequent handling and assembly and to protect the brittle material. The model coil which is made of Nb 3 Sn CICC will undergo a high temperature diffusion reaction according to the optimum heat treatment schedule for the Nb 3 Sn/RRP ® superconducting strand. The facility specialized in the heat treatment of Nb 3 Sn superconducting coils has been established in CHMFL, and several kinds of monitoring instruments are equipped to monitor impurities in the argon gas during heat treatment. At present, the heat treatment of the model coil has been finished and the performance test results of the model coil meet our requirements. This paper mainly presents the introduction of the heat treatment facility, details of heat treatment process for the model coil, and some simulations of the states during heat treatment. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10948-012-1554-9 Authors P. He, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China Z. M. Chen, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China W. G. Chen, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China G. L. Kuang, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China Z. Y. Chen, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China P. C. Huang, High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Pr–Fe–B/Fe/Pr–Fe–B films with different Fe layer thicknesses were deposited by magnetron sputtering on Si (100) substrate heated at 650 °C. Structural and magnetic properties of the Pr–Fe–B/Fe/Pr–Fe–B films were investigated. X-ray diffraction and magnetic measurement results reveal that the Pr–Fe–B/Fe/Pr–Fe–B films are anisotropic when the thickness of Fe layer is smaller than 50 nm. The enhancement of the saturation magnetization in nanocomposite films is attributed to the exchange coupling between the soft and hard phases. The highest coercivity of about 13.9 kOe is achieved in the Mo(50 nm)/Pr–Fe–B(50 nm)/Mo(2 nm)/Fe(2 nm)/Mo(2 nm)/Pr–Fe–B(50 nm)/Mo(50 nm) film and increasing the thickness of soft-magnetic layer results in a continuous decreasing of the coercivity. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1563-8 Authors F. Yang, Shenyang National Laboratory for Materials Science, Institute of Metal Research and International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang, 110016 China W. Liu, Shenyang National Laboratory for Materials Science, Institute of Metal Research and International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang, 110016 China W. B. Cui, Shenyang National Laboratory for Materials Science, Institute of Metal Research and International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang, 110016 China J. N. Feng, Shenyang National Laboratory for Materials Science, Institute of Metal Research and International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang, 110016 China Z. D. Zhang, Shenyang National Laboratory for Materials Science, Institute of Metal Research and International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang, 110016 China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    A systematic study on phase evolution, bulk density, resistivity, critical transition temperature ( T C ), critical current density ( J C ) and in-field transport critical current density ( J C – B ) of pure and nano particles of BaHfO 3 added YBa 2 Cu 3 O 7− δ (YBCO) samples of different weight percentages has been carried out. The result shows a significant improvement in the electrical transport properties of the superconductor, namely the J C , J C – B characteristics and flux pinning force ( F p ) of the BaHfO 3 added samples. The transition temperature also was found to increase marginally. A maximum transport J C of 742 A/cm 2 at 77 K (for x =2 wt%) was observed for BaHfO 3 added samples against 147 A/cm 2 for pure YBCO sample. The enhancement of the critical current density in the YBCO–BaHfO 3 sample is attributed to the formation of an insulating and non-reacting YBa 2 HfO 5.5 phase, acting as artificial pinning centers in the matrix. The introduction of nano particles of BaHfO 3 in bulk YBCO increases the pinning force density from 30×10 3  N/m 3 to 424×10 3  N/m 3 at 77 K. The improvement in sintering density due to an optimum value 2 wt% BaHfO 3 addition in bulk YBCO indicates its potential use in electrical devices and technology. The enhancement in the superconducting properties, particularly in the J C – B characteristics due to BaHfO 3 addition, seems to have great technological significance. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10948-012-1558-5 Authors P. P. Rejith, Electronic Materials Research Laboratory, Department of Physics, Mar Ivanios College, Thiruvananthapuram, 695 015 Kerala, India S. Vidya, Electronic Materials Research Laboratory, Department of Physics, Mar Ivanios College, Thiruvananthapuram, 695 015 Kerala, India J. K. Thomas, Electronic Materials Research Laboratory, Department of Physics, Mar Ivanios College, Thiruvananthapuram, 695 015 Kerala, India Sam Solomon, Department of Physics, St. John’s College, Anchal, 691306 Kerala, India Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The structural effects of Cu doping in (Ru 1− x Cu x )(Sr 1.47 Ba 0.2 Nd 0.33 )(NdCe)Cu 2 O 10− δ (0≤ x ≤0.5) have been investigated by using X-ray and neutron diffraction. X-ray diffraction showed that the phase purity of the samples increased as the Cu-doping concentration increased and nearly-single-phase materials could be obtained for samples with x ≥0.25. The Rietveld refinements of the neutron diffraction data around 5 K for x =0.25 and x =0.5 samples show that the oxygen vacancies are located on both the O(1) site of the RuO 2 basal plane and the O(4) site of the fluorite-type (Nd,Ce)O 2− δ block, and the overall oxygen content is found to decrease with increasing Cu content x , mainly due to an increase in oxygen vacancies located on the O(1) site. It is also observed that the rotation angle of the RuO 6 octahedra away from the crystallographic c -axis increases as the Cu content x increases. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1553-x Authors H. K. Lee, Department of Physics, Kangwon National University, Chuncheon, 200-701 Republic of Korea Y. I. Kim, Korea Research Institute of Standards and Science, Daejeon, 305-340 Republic of Korea Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Magnetic properties of NiFe/Zr multilayer films, prepared by DC magnetron sputtering, have been studied by vibrating sample magnetometer and ferromagnetic resonance (FMR). Spin-wave resonances were observed in Ni 81 Fe 19 /Zr multilayer films in FMR experiments, and the spin wave was found to be sustained by both the whole films. Estimated small interlayer coupling constant shows weak exchange coupling effect between NiFe layers across Zr spacers. The FMR linewidth, in parallel geometry, of the uniform mode was found to increase with decreasing NiFe thickness (20 Å ≤ ≤ 120 Å) indicating that it corresponds to an interfacial effect. In addition, electronic and magnetic properties of multilayers are investigated by self-consistent ab initio calculations based on Korringa–Kohn–Rostocker (KKR). Spin polarized within the framework of the Coherent Potential Approximation (CPA) is considered for calculations. Content Type Journal Article Category Review Paper Pages 1-5 DOI 10.1007/s10948-012-1536-y Authors Z. Yamkane, Laboratoire de Physique des Matériaux, Micro-électronique, Automatique et thermique, Faculté des Sciences Ain Chock, Université Hassan II, B.P. 5366, Mâarif, Route d’El Jadida, km-8, Casablanca, Morocco H. Lassri, Laboratoire de Physique des Matériaux, Micro-électronique, Automatique et thermique, Faculté des Sciences Ain Chock, Université Hassan II, B.P. 5366, Mâarif, Route d’El Jadida, km-8, Casablanca, Morocco N. Omari, Laboratoire de Physique des Matériaux, Micro-électronique, Automatique et thermique, Faculté des Sciences Ain Chock, Université Hassan II, B.P. 5366, Mâarif, Route d’El Jadida, km-8, Casablanca, Morocco E. K. Hlil, Institut Néel, CNRS—Université Joseph Fourier, BP 166, 38042 Grenoble, France Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Within the kinetic energy driven superconductivity, the magnetic field dependent penetration depth in cuprate superconductors is studied in the linear response approach. The electromagnetic response kernel is evaluated by considering both couplings of the electron charge and electron magnetic momentum with a weak magnetic field and employed to calculate the penetration depth based on the specular reflection model, then the main features of the magnetic field dependent penetration depth are well reproduced. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1541-1 Authors Zheyu Huang, Department of Physics, Beijing Normal University, Beijing, 100875 China Huaisong Zhao, Department of Physics, Beijing Normal University, Beijing, 100875 China Yu Lan, Department of Physics, Jinan University, Guangzhou, 510632 China Shiping Feng, Department of Physics, Beijing Normal University, Beijing, 100875 China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We analyze the vortex dynamics in superconducting thin films with a periodic array of pinning centers. In particular, we study the effect of anisotropy for a Kagomé pinning network when longitudinal and transverse transport currents are applied. By solving the equations of motion for the vortex array numerically at zero temperature, we find different phases for the vortex dynamics, depending on the pinning and driving force. An unusual sequence of peaks for driving force along and perpendicular to the main lattice axes is observed for the differential resistance, reflecting the anisotropy of the transport properties and the complex behavior of the vortex system. This behavior may be understood in terms of interstitial pinning vacancies, which create channels of vortices with different pinning strengths. Content Type Journal Article Category Original Paper Pages 1-3 DOI 10.1007/s10948-012-1532-2 Authors R. P. Simões, Faculdade de Ciências, Departamento de Física, Unesp-Universidade Estadual Paulista, Bauru, CP 473, SP 17033-360, Brazil P. A. Venegas, Faculdade de Ciências, Departamento de Física, Unesp-Universidade Estadual Paulista, Bauru, CP 473, SP 17033-360, Brazil D. F. Mello, Faculdade de Ciências, Departamento de Física, Unesp-Universidade Estadual Paulista, Bauru, CP 473, SP 17033-360, Brazil Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    MgB 2 thin films were fabricated on MgO (100) single crystal substrates. First, deposition of boron was performed by rf magnetron sputtering on MgO substrates and followed by a post deposition annealing at 850 °C in magnesium vapor. In order to investigate the effect of FeO nanoparticles on magnetic properties of MgB 2 thin films, the films were coated with different concentrations of FeO nanoparticles by spin coating process. The magnetic field dependence of the critical current density was calculated from the M – H loops and also magnetic field dependence of the pinning force density was determined for the films containing different concentrations of FeO nanoparticles. The values of the critical current density in zero field at 5 K was found to be around 1×10 6  A/cm 2 for pure MgB 2 film, 1.4×10 6 for MgB 2 film coated with 25 %, 7.2×10 5 for MgB 2 film coated with 33 %, 9.1×10 5 for MgB 2 film coated with 50 % and 1.1×10 6  A/cm 2 for MgB 2 film coated with 100 %. It was found that the film coated with 25 % FeO nanoparticles has slightly enhanced critical current density and it can be noted that especially the film coated with 25 % FeO became stronger in the magnetic field. The films coated with FeO were successfully produced and they indicated the presence of artificial pinning centers created by FeO nanoparticles. The superconducting transition temperature of the film coated with 25 % FeO nanoparticles was determined by moment–temperature ( M – T ) measurement to be 34 K which is 4 K higher than that of the pure film. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10948-012-1533-1 Authors E. Taylan Koparan, Physics Department, Karadeniz Technical University, Trabzon, 61080 Turkey A. Surdu, Institute of Electronic Engineering and Industrial Technologies ASM, 2028 Chisinau, Republic of Moldova A. Awawdeh, Institute of Electronic Engineering and Industrial Technologies ASM, 2028 Chisinau, Republic of Moldova A. Sidorenko, Institute of Electronic Engineering and Industrial Technologies ASM, 2028 Chisinau, Republic of Moldova E. Yanmaz, Physics Department, Karadeniz Technical University, Trabzon, 61080 Turkey Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Zn 1− x Co x O ( x =0, 0.005, 0.01, 0.02, 0.03, 0.06, 0.12) powders have been synthesized by the microemulsion method. XRD patterns confirm the pure wurtzite structure without any impurity phase. TEM images illustrate that Zn 1− x Co x O particles are formed by aggregation of small crystallites. The magnetization measurements show clear room-temperature ferromagnetism in Zn 1− x Co x O ( x =0, 0.005, 0.01), and the saturated ferromagnetic magnetization increased with increasing Co concentration to 0.01. However, the ferromagnetic magnetization decreased drastically with further increasing Co concentration ( x 〉0.01). PL spectra clearly show an increasing concentration of oxygen vacancies with increasing Co concentration to 0.01, and strong suppression of oxygen vacancies with further increasing Co concentration in Zn 1− x Co x O. We conclude that the high concentration of oxygen vacancies is the key origin for the observed ferromagnetism in Co-doped ZnO. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10948-012-1535-z Authors Liguo Xu, School of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016 China Hua Zhang, Department of Physics, Southeast University, Nanjing, 211189 China Kai Shen, School of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016 China Mingxiang Xu, Department of Physics, Southeast University, Nanjing, 211189 China Qingyu Xu, Department of Physics, Southeast University, Nanjing, 211189 China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Ni/NM multilayers (with noble metal NM=Au,Ag and Cu) were prepared by the electron beam evaporation method under ultra high vacuum conditions. The magnetic properties of Ni/NM multilayers are examined as a function of Ni layer thickness t Ni . The temperature dependence of the spontaneous magnetization M ( T ) is well described by a T 3/2 law in all multilayers. A spin-wave theory has been used to explain the temperature dependence of the magnetization and the approximate values for the bulk Exchange interaction J b and surface exchange interaction J s for various Ni layer thicknesses have been obtained. In the other hand we have used the high-temperature series expansion technique, to analyze the phase transition and the critical phenomena of a ferromagnetic a two-component multilayer, through three models: Ising, XY and Heisenberg. The critical reduced temperature τ c ( ν ) is studied as function of the thickness of constituents in the unit cell of the multilayer. In the two-component multilayer τ c ( ν ) is studied as function of the exchange interaction in each material and within the interface J s , J b and J ⊥ , respectively. A critical value of the surface exchange interaction in the film and interface exchange interaction in the multilayer above which the surface and the interface magnetism appears is obtained. The dependence of the reduced critical temperature on the thickness of the film and the unit cell of multilayer has been investigated. The effects of an amorphous magnetic surface on the critical properties of the film of simple cubic lattice have been studied. A number of characteristic behaviors, such as the possibility of the existence of a critical length of the unit cell thickness at which the temperature of the multilayer remains insensitive to the exchange coupling within interface, are reported. In a defined range of the exchange interactions, the values of γ are comparable to the universal ones and are independent of the film thickness. The asymmetry of the structure and the competition of the effects of the exchange coupling are important for the magnetic properties of the system. Content Type Journal Article Category Original Paper Pages 1-15 DOI 10.1007/s10948-012-1546-9 Authors R. Masrour, Laboratory of Materials, Processes, Environment and Quality, National School of Applied Sciences, Cady Ayyed University, Route Sidi Bouzid, BP 63, 46000 Safi, Morocco M. Hamedoun, Institute for Nanomaterials and Nanotechnologies, Rabat, Morocco A. Benyoussef, LMPHE, Faculté des Sciences, Université Mohamed V, Rabat, Morocco H. Lassri, LPMMAT, Faculté des Sciences Ain Chock, Université Hassan II, Casablanca, Morocco Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The Weyl–Dirac fermions in graphene-based SG/I/SG (SG denoting superconducting graphene; I, an insulator) junctions subjected to strains become highly asymmetric. The effect of the strain-induced symmetry change of the fermions on the supercurrent is studied. The highly anisotropic velocity near the critical deformation causes the critical current parallel to the direction of strain to oscillate as a function of gate voltage at a very high frequency. The same anisotropic velocity destroys the oscillation of the gate-dependent critical current when the current is perpendicular to the direction of strain. The direction-dependent supercurrent is due to the strain turning the two-dimensional massless relativistic electrons into nearly one-dimensional massless relativistic fermions near the critical deformation. This work reveals that a new effect can be induced by applying strain on a graphene-based Josephson junction. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10948-012-1543-z Authors Bumned Soodchomshom, Department of Physics, Faculty of Science, Kasetsart University, Bangkok, 10900 Thailand I-Ming Tang, Department of Physics, Faculty of Science, Mahidol University, Bangkok, 10400 Thailand Rassmidara Hoonsawat, Department of Physics, Faculty of Science, Mahidol University, Bangkok, 10400 Thailand Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In various ( x =0–1), members of the 11-iron-pnictide superconductor family, the temperature dependent resistivity ρ can be scaled into a universal curve. It is found that the ρ ( T ) dependences can be reproduced by the expressions and for x =0–0.3 and 0.4–1.0, respectively. The scaling was performed using the energy scale 2 Δ , the parameter c , and the residual resistivity ρ 0 as scaling parameters. The compositional variation of the scaling parameters 2 Δ and ρ 0 has been determined. The existence of a universal metallic ρ ( T ) curve is interpreted as an indication of a single mechanism which dominates the scattering of the charge carriers in FeTe 1− x Se x ( x =0–1). Thus, the scaling of the normal-state properties seems to be a general feature not only for high- T c cuprates but also for the iron-pnictides superconductor family. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10948-012-1531-3 Authors E. Arushanov, Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden - IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany S. Levcenko, Institute of Applied Physics, Academy of Sciences of Moldova, 2028 Chisinau, Moldova G. Fuchs, Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden - IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany S. L. Drechsler, Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden - IFW Dresden, Helmholtzstr. 20, 01069 Dresden, Germany Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We explore the spin-dependent transport properties in a molecular junction model made of heterocyclic molecules such as poythiophene, polyfuran, and polypyrrole sandwiched between ferromagnetic three-dimensional electrodes, hereafter named FM/h-molecule/FM junction, based on a tight-binding model and a generalized Green’s function method in the Landauer–Büttiker formalism. The coherent spin-dependent transport through the energy levels of heterocyclic molecules, the transmittance, current–voltage ( I – V ) characteristics, and the tunnel magnetoresistance (TMR) of the FM/h-molecule/FM junction are numerically investigated. It is found that the spin-dependent transport properties are importantly influenced by the heteroatoms in the heterocyclic molecules. It is shown that the TMR of the molecular junction can be quite large (over 69 %) depending on the applied voltage and the molecular field of the FM electrodes. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10948-012-1544-y Authors A. Ahmadi Fouladi, Department of Physics, Science and Research Branch, Islamic Azad University, Tehran, Iran S. A. Ketabi, School of Physics, Damghan University, Damghan, Iran S. M. Elahi, Department of Physics, Science and Research Branch, Islamic Azad University, Tehran, Iran S. A. Sebt, Department of Physics, Science and Research Branch, Islamic Azad University, Tehran, Iran Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    A material, when superconductive, has an electrical resistance of exactly zero below a critical temperature ( T c ). This is universal in superconductors. We firstly verify our approaches by comparing our preliminary calculations for resistance with previous available measurements. After the intensive computations, we illustrate the effect of activation volume and energy on the enhancement of T c (up to 50 K) for the Cs x Fe 2− y Se 2− z (0≤ x , y , z ≤1) superconductor by using the verified Eyring’s transition-state approach which is based on the quantum chemistry to treat the activated complex: Cs x Fe 2− y Se 2− z . Our results suggest that tuning activation volume is the efficient way to enhance the superconducting temperature. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1748-1 Authors Chu W. Kwang-Hua, Transfer Centre, No. 24, 260th Lane, First Section, Road Muja, Taipei, 116 Taiwan ROC Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In this study, samples with nominal composition of Bi 2 Sr 2 Ca 1 Cu 2− x Yb x O y , where x =0.0, 0.05, 0.1 and 0.25, have been textured using the Laser Floating Zone technique. The effects of different Yb doping on the structure have been investigated by electrical resistivity, scanning electron microscopy, XRD, mechanical and dc-magnetization techniques. It has been found that with increasing Yb 3+ doping for Cu, the physical and superconducting properties of structure gradually decrease. J C values, calculated using the Bean’s model, significantly change, although T C is approximately the same for all samples. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1725-8 Authors H. Gündoğmuş, Department of Physics, Faculty of Sciences and Letters, Çukurova University, 01330 Adana, Turkey B. Özçelik, Department of Physics, Faculty of Sciences and Letters, Çukurova University, 01330 Adana, Turkey B. Özkurt, Department of Electronic and Computer Education, Faculty of Tarsus Technical Education, University of Mersin, Mersin, Turkey A. Sotelo, ICMA (CSIC-Universidad de Zaragoza), María de Luna, 3, 50018 Zaragoza, Spain M. A. Madre, ICMA (CSIC-Universidad de Zaragoza), María de Luna, 3, 50018 Zaragoza, Spain Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We present a study of magnetization and magnetocaloric effect for the SmMnO 3 compound. This compound was synthesized by combustion reaction and its magnetic and structural properties studied by X-ray powder diffraction (XRD) and magnetization ( M ) measurements as a function of temperature and under magnetic fields. The XRD pattern at room temperature confirmed the presence of a single phase with orthorhombic structure. From magnetization versus temperature, we observe two magnetic orderings, the first one at 6 K due to Sm 3+ , and the other one at T N =57(2) K is the anti-ferromagnetic long-range ordering. The magnetic entropy change, Δ S M , was obtained from magnetization isotherms close to T N where it reaches a maximum value of about 8.0 J/kg K for an applied field of 7 T. Content Type Journal Article Category Original Paper Pages 1-3 DOI 10.1007/s10948-012-1727-6 Authors Cláudia A. da Silva, Departamento de Física, Universidade Federal de Sergipe, 49100-000 São Cristovão, SE, Brazil Raul S. Silva, Departamento de Física, Universidade Federal de Sergipe, 49100-000 São Cristovão, SE, Brazil E. J. R. Plaza, Departamento de Física, Universidade Federal de Sergipe, 49100-000 São Cristovão, SE, Brazil N. O. Moreno, Departamento de Física, Universidade Federal de Sergipe, 49100-000 São Cristovão, SE, Brazil Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We calculate the structural and electronic properties of the Zr x Al 1− x N in cubic phase using first-principles total energy calculations. The study is based on the functional density theory, DFT, with Augmented Plane Wave Plus Local Orbitals method for Calculating Crystal Properties (FP-LAPW). Determination of the crystal lattice constant, the volume of the unit cell, the bulk modulus for concentrations x =0.25,0.50,0.75, is carried out. In addition, we also study the electronic properties for each x . The study consists of the analysis of the electrons energy versus the wave vector, in some directions of the first Brillouin zone, and the Density of States (DOS) as a function of the energy. The results show that the lattice constant increases with x , but the functional relations are not linear. On the other hand, the electronic properties vary substantially with x , and a possible semiconductor metal transition is predicted for any x 〈0.25. Content Type Journal Article Category Original Paper Pages 1-3 DOI 10.1007/s10948-012-1728-5 Authors Edgardo D. Gutiérrez-Senior, Grupo de Investigación en Teoría de la Materia Condensada, Universidad del Magdalena, Santa Marta, Colombia Jairo Arbey Rodríguez M., GEMA—Grupo de Estudio de Materiales, Universidad Nacional de Colombia, Bogotá, Colombia J. Sierra-Ortega, Grupo de Investigación en Teoría de la Materia Condensada, Universidad del Magdalena, Santa Marta, Colombia Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Maghemite and silver nanoparticles were prepared using the ionic coordination reaction technique. X-ray diffractograms (XRD) show that all the samples have a high degree of purity. The average particle sizes obtained by XRD and transmission electron microscopy (TEM) vary from 9 to 13 nm for the γ –Fe 2 O 3 particles and from 130 to 142 nm for the Ag particles. The magnetic properties of the samples have been studied by room-temperature DC magnetization and Mössbauer spectroscopy. These measurements indicate the presence of γ –Fe 2 O 3 particles with interparticle interactions of varying strength, resulting in three magnetic regimes: superparamagnetic, superparamagnetic with interactions, and blocked with interactions. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1720-0 Authors J. M. Soares, Departamento de Física, Universidade do Estado do Rio Grande do Norte, 59610-010 Mossoró, RN, Brazil D. S. Chaves, Departamento de Física, Universidade do Estado do Rio Grande do Norte, 59610-010 Mossoró, RN, Brazil O. L. A. Conceição, Departamento de Física, Universidade do Estado do Rio Grande do Norte, 59610-010 Mossoró, RN, Brazil A. L. Gurgel, Departamento de Física, Universidade do Estado do Rio Grande do Norte, 59610-010 Mossoró, RN, Brazil M. M. Xavier Jr., Departamento de Ciências Exatas e Naturais, Universidade Federal Rural do Semi-Árido, 59625-900 Mossoró, RN, Brazil M. A. Morales, Departamento de Ciências Exatas e Naturais, Universidade Federal Rural do Semi-Árido, 59625-900 Mossoró, RN, Brazil E. M. Baggio-Saitovitch, Centro Brasileiro de Pesquisas Físicas, 22290-180 Rio de Janeiro, RJ, Brazil Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Complete high-order perturbation formulas are established in ZnSe:Ti 2+ , CdTe:Ti 2+ , and ZnSe:V 3+ crystals, based not only on the contributions of the spin-orbit coupling effect of the central ion and the ligands, but also on that of the charge-transfer levels. The electron paramagnetic resonance (EPR) g -factors are calculated from the formulas and the calculated values of the EPR g -factors agree well with the experimental ones. The contribution rate of the charge-transfer levels (|Δ g T /Δ g F |) are 10.1 %, 7.6 %, and 24.9 % for ZnSe:Ti 2+ , CdTe:Ti 2+ , and ZnSe:V 3+ crystals, respectively. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1738-3 Authors Lianxuan Zhu, Department of Physics, Henan Agricultural University, NO.63 Nongye Road, Zhengzhou, Henan 450002, China Minjie Wang, Department of Physics, Henan Agricultural University, NO.63 Nongye Road, Zhengzhou, Henan 450002, China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Co 0.5 Ni X Fe (0.5− X ) Fe 2 O 4 of composition ( X =0.1 to 0.5) has been prepared by sol gel auto combustion citrate nitrate method. The molar ratio of metal nitrates to citric acid was maintained as 1:3 to obtain the small crystallite size. A systematic study of XRD, impedance, ac conductivity and dielectric studies of the samples were carried out in the present work. A semiconducting to metallic changeover accompanied by the grain boundary effect gradually replaced by grain contribution has been found from the impedance analysis. Confirmation of phase transition is also obtained from ac conductivity and dielectric analysis of activation energy graph where the slope changes from negative to positive. Nickel doped cobalt ferrite exhibits a semiconducting nature up to 513 K for all the compositions and underwent to metallic phase above 513 K. It is attributed to cation distribution between A and B sites as a function of temperature. Content Type Journal Article Category Original Paper Pages 1-10 DOI 10.1007/s10948-012-1705-z Authors D. Vanidha, Department of Physics, Pondicherry Engineering College, Puducherry, 605014 India A. Arunkumar, Department of Physics, Pondicherry Engineering College, Puducherry, 605014 India S. Rajagopan, Department of Chemistry, Pondicherry Engineering College, Puducherry, 605014 India R. Kannan, Department of Physics, Pondicherry Engineering College, Puducherry, 605014 India Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In this paper, we solve the time dependent Ginzburg–Landau (TDGL) equations in two dimensions, using Lattice–Boltzmann (LB) technique and the velocity discretization scheme D 2 Q 9, for a square region with periodic boundary conditions. In order to obtain the solution, we use three distribution functions, each of them obeying the LB equation, and making a proper redefinition of the tensor Π 0 , we find the (TDGL) equations. Further, we obtain the equilibrium distribution functions for the three LB equations, and then the solution for the components of the magnetic potential vector and the order parameter. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1722-y Authors F. Fonseca, Departamento de Física, Universidad Nacional de Colombia, Cra 30 cl 45 Ciudad Universitaria, Bogotá, D.C., Colombia Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Electronic and phonon structures of the BaFe 2 As 2 superconductor in the magnetic–orthorhombic phase have been investigated by the ab-initio density functional theory using the pseudopotential Quantum Espresso code. Density of state and electronic band structure for this phase has been studied, but phonon dispersion has been obtained only for the nonmagnetic–orthorhombic phase. Electronic band structure and density of states are in good agreement with other calculations in the literature. The electronic state near the Fermi energy are essentially made from Fe3 d and As4 p orbital that indicate in-plane conductivity in FeAs layers in this system. Comparing calculated phonon dispersions with experimental data justify magnetic dependence of some phonon modes. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10948-012-1717-8 Authors M. Sandoghchi, Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran, Iran H. Khosroabadi, Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran, Iran H. Almasi, Department of Physics, Sharif University of Technology, P.O. Box 11365-9161, Tehran, Iran M. Akhavan, Magnet Research Laboratory (MRL), Department of Physics, Sharif University of Technology, P.O. Box 11365-916, Tehran, Iran Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    a-C:H films were grown by plasma-enhanced chemical vapor deposition in atmospheres composed by 30 % of acetylene and 70 % of argon. Radiofrequency signal (RF) was supplied to the sample holder to generate the depositing plasmas. Deposition time and pressure were chosen 300 s and 9.5 Pa, respectively, while the excitation power changed from 5 to 125 W. The films were exposed to a post-deposition treatment during 300 s in RF-plasmas (13.56 MHz, 70 W) excited from 13.33 Pa of SF 6 . Raman and X-ray photoelectron spectroscopy were used to evaluate the microstructure and chemical composition of the films. The thickness was measured by perfilometry. Hardness and friction coefficient were determined from nanoindentation and risk tests, respectively. With increasing power, the film thickness reduced, but a further shrinkage occurred upon the fluorination process. After that, the molecular structure was observed to vary with deposition power. Fluorine was detected in all samples replacing H atoms. Consistently with the elevation in the proportion of C atoms with sp 3 hybridization, hardness increased from 2 to 18 GPa. Friction coefficient also increased with power due to the generation of dangling bonds during the fluorination process. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1729-4 Authors N. M. Santos, UNESP, Campus Experimental de Sorocaba, Sorocaba, SP, Brazil R. P. Mota, UNESP, Guaratinguetá, SP, Brazil R. Y. Honda, UNESP, Guaratinguetá, SP, Brazil M. A. Algatti, UNESP, Guaratinguetá, SP, Brazil K. G. Kostov, UNESP, Guaratinguetá, SP, Brazil M. E. Kayama, UNESP, Guaratinguetá, SP, Brazil P. A. P. Nascente, Departamento de Engenharia de Materiais, UFSCar, São Carlos, SP, Brazil N. C. Cruz, UNESP, Campus Experimental de Sorocaba, Sorocaba, SP, Brazil E. C. Rangel, UNESP, Campus Experimental de Sorocaba, Sorocaba, SP, Brazil Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We report the magnetism properties on single crystal of Ca 2 FeMoO 6 double perovskite prepared by a floating zone technique. This high quality material has been studied by X-ray powder diffraction (XRD), and magnetic measurements. The field dependence of the magnetization at 5 K, 100 K, and 300 K suggest a ferrimagnetic behavior with a saturation magnetic moment of approximately 2.1 μ B , 2.0 μ B , and 1.4 μ B per formula unit, respectively. From dc susceptibility, we observed two magnetic transitions at T C1 =380 K (paramagnetic–ferrimagnetic) and T C1 =336 K (orthorhombic–monoclinic phase). Content Type Journal Article Category Original Paper Pages 1-3 DOI 10.1007/s10948-012-1723-x Authors N. O. Moreno, Departamento de Física, Universidade Federal de Sergipe, São Cristovão, SE 49100-000, Brazil L. B. Barbosa, Departamento de Física, Universidade Federal de Sergipe, Itabaiana, SE, Brazil D. Reyes Ardila, Departamento de Física, Universidade Federal de Sergipe, Itabaiana, SE, Brazil J. P. Andreeta, Departamento de Física e Ciência dos Materiais, Instituto de Física de São Carlos, CP 369, 13560-590 São Carlos, SP, Brazil Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The Hubbard model has been investigated widely by many authors, while this work may be new in two aspects. One, we focus on the possible effects of the positions of the gaps associated with the pairing and the spin density wave. Two, we suggest that the models with different parameters are appropriate for different materials (or a material in different doped regions). This will lead to some new insights into the high temperature superconductors. It is shown that the SDW can appear at some temperature region when the on-site Coulomb interaction is larger, while the SC requires a decreased U at a lower temperature. This can qualitatively explain the relationship between superconducting and pseudogap states of Cu-based superconductors in underdoped and optimally doped regions. The superinsulator is also discussed. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1744-5 Authors Tian De Cao, Department of Physics, Nanjing University of Information Science & Technology, Nanjing, 210044 China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The existence of spontaneous magnetization of an eutectic In 0.15 Ga 0.85 -sapphire interface is confirmed by magnetic torque measurements. Its phase diagram on H – T plane spreads above room temperature along the T -axis and is restricted to 2–2.5 T along the H -axis at T ≤100 K. Content Type Journal Article Category Original Paper Pages 1-3 DOI 10.1007/s10948-012-1750-7 Authors V. I. Nizhankovskii, International Laboratory of High Magnetic Fields and Low Temperatures, Gajowicka 95, Wroclaw, 53-421 Poland Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Trilayers made of perovskite-type ferromagnetic (F), antiferromagnetic (AF) and superconducting (S) films were fabricated and their microstructural properties studied. Epitaxially strained La 2/3 Ca 1/3 MnO 3 /La 1/3 Ca 2/3 MnO 3 /YBa 2 Cu 3 O 7− δ (F/AF/S) trilayers were grown in situ by dc-sputtering technique onto (001)-oriented SrTiO 3 (STO) substrates. Whereas the thickness of the bottom (F) and top (S) layer was fixed to 74 nm and 100 nm, respectively, that of the intermediate AF layer was varied between ∼4 nm and ∼9 nm. The crystalline quality of the samples was checked by X-Ray diffraction (XRD) analysis. The θ –2 θ scans and reciprocal space maps at (002) and (013) Bragg reflections provided clear evidence for the heteroepitaxial growth of the trilayers as well as for the absence of secondary phases. Due to high epitaxiality of the trilayers, their magnetic response was already shown to develop an excellent magnetic anisotropy to clearly visualize the superconducting diamagnetism and ferromagnetic behavior at a same temperature. The superconducting diamagnetic response at 5 K has now been used to calculate the superconducting current density of the S layer as a function of an applied magnetic field. The results confirmed the uncoupling role of the AF layer. The presence of well defined AF barriers (La 1/3 Ca 2/3 MnO 3 ) in the trilayers was also evidenced by recording the I – V characteristic in cross configuration, which showed an anisotropic behavior as well. The results achieved suggest that such oxide heterostructures could play an important role in the search for novel devices based on magnetic junctions. Content Type Journal Article Category Letter Pages 1-6 DOI 10.1007/s10948-012-1746-3 Authors E. Baca, Grupo de Ingeniería de Nuevos Materiales, Universidad del Valle, A.A. 25360, Cali, Colombia O. Morán, Laboratorio de Materiales Cerámicos y Vítreos, Universidad Nacional de Colombia, Sede Medellín, A.A. 568, Medellín, Colombia W. Saldarriaga, Laboratorio de Materiales Cerámicos y Vítreos, Universidad Nacional de Colombia, Sede Medellín, A.A. 568, Medellín, Colombia P. Romano, Dipartimento di Scienze per la Biologia, la Geologia e l’Ambiente, Università del Sannio, via Port’Arsa 11, 82100 Benevento, Italy A. Polcari, Dipartimento di Scienze per la Biologia, la Geologia e l’Ambiente, Università del Sannio, via Port’Arsa 11, 82100 Benevento, Italy A. Guarino, CNR-SPIN UOS Salerno, via Ponte Don Melillo, 84084 Fisciano, SA, Italy A. Vecchione, CNR-SPIN UOS Salerno, via Ponte Don Melillo, 84084 Fisciano, SA, Italy Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Vortex charges in high-temperature superconductors (HTS) with a different hole-doped level are investigated by Bogoliubov–de Gennes equations based on a model Hamiltonian with competing antiferromagnetic (AFM) and d -wave superconducting order (DSC). Our results show that the AFM order inside the vortex core becomes significant for the underdoped sample, which competes with the DSC order through expulsion of the holes from outside the vortex core and leads to a negative vortex charge, whereas the vortex charge shows a double-vortex center with a positively charged core and a negatively charged core for a slightly overdoped level; and the positive vortex charge may occur for a highly hole-doped level. Moreover, local density of states indicates that the presence of the AFM order in the vortex core provides a mechanism for splitting of the zero-bias conductance peak into local peaks at the core center. Content Type Journal Article Category Original Paper Pages 1-5 DOI 10.1007/s10948-012-1752-5 Authors Lin Peng, School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai, 200090 China Yong-sheng Liu, School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai, 200090 China Hai-ning Hu, School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai, 200090 China Yu-feng Zhang, School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai, 200090 China Yan Xu, School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai, 200090 China Zhi-yong Liu, Department of Physics, Shanghai University, Shanghai, 200444 China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Polycrystalline thick films with the nominal composition [(Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O x ] 1− x (La 0.7 Sr 0.3 MnO 3 ) x ( x =0, 0.01, 0.03, 0.05) were prepared by the melting-quenching-annealing (MQA) method on (001)-oriented LaAlO 3 (LAO) substrates. The XRD patterns show that the samples are composites consisting of (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O x and La 0.7 Sr 0.3 MnO 3 particles with average grain sizes of ∼60 and ∼30 nm, respectively. From electric transport measurements, the superconducting onset temperature, T onset , and superconducting critical temperature, T c , ended up being ∼80 and ∼60 K, respectively. The depression of T c may be attributed to the proximity effect between ferromagnetism and superconductivity. The M – H hysteresis loops indicate the coexistence of ferromagnetism and superconductivity in the films. The magnetic field dependence of the superconducting current density and the volume pinning force F p = J c × B were obtained by applying Bean’s model to the isothermal M – H loops. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10948-012-1745-4 Authors O. Paredes, Centro de Investigaciones en Materiales, Facultad de Ingeniería, Universidad de Nariño, Ciudad Universitaria Torobajo, Pasto, Colombia E. Baca, Grupo de Ingeniería de Nuevos Materiales, Departamento de Física, Universidad del Valle, A.A. 25360 Cali, Colombia O. Morán, Laboratorio de Materiales Cerámicos y Vítreos, Departamento de Física, Universidad Nacional de Colombia, Sede Medellín, A.A. 568 Medellín, Colombia Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    Dense superconducting composites with magnetic nanoparticles were prepared by spark plasma sintering. In addition to structure and magnetic properties, we focused on the pinning properties as described by the field and temperature dependence of the scaled pinning force analyzed. We found that the pinning force does not obey any scaling law and attributed this effect to the anisotropy of the MgB 2 and the almost random distribution of the orientation of the superconducting grains within the polycrystalline sample. Content Type Journal Article Category Original Paper Pages 1-7 DOI 10.1007/s10948-012-1732-9 Authors V. Sandu, National Institute of Materials Physics, Magurele, 077125 Romania Ching Yern Chee, Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Lembah Pantai, Kuala Lumpur, Malaysia Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    This study indicates the change of the electrical, microstructural, physical, mechanical and superconducting properties of Cu-diffused bulk MgB 2 superconductors by means of scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), microhardness and dc resistivity measurements. The samples are prepared at different annealing temperatures in the range from 650 to 850  ∘ C. Electrical and superconducting properties of samples are estimated from the dc electrical resistivity measurements. Moreover, microhardness measurements are performed to investigate the mechanical properties. Further, phase composition, grain sizes and lattice parameters are determined from the XRD measurements. At the same time, the surface morphology and grain connectivity of the samples are examined by SEM investigations. The measurements conducted demonstrate that both the Cu diffusion into the MgB 2 system and the increment in the diffusion-annealing temperature increase the critical transition temperatures. Similarly, microstructure and grain size improve while the voids and porosity decrease with the increase of the diffusion-annealing temperature. In addition, the experimental results of the microhardness measurements are investigated using the Meyer’s law, PSR (proportional specimen resistance), modified PRS (MPSR), elastic-plastic deformation model (EPD) and Hays–Kendall (HK) approach. The obtained microhardness values of the samples decrease with the increase of the diffusion-annealing temperature up to 850  ∘ C. The Hays–Kendall approach is found to be the most successful model describing the mechanical properties of the samples studied in this work. Content Type Journal Article Category Original Paper Pages 1-9 DOI 10.1007/s10948-012-1719-6 Authors M. Dogruer, Department of Physics, Abant Izzet Baysal University, Bolu, 14280 Turkey G. Yildirim, Department of Physics, Abant Izzet Baysal University, Bolu, 14280 Turkey O. Ozturk, Department of Physics, Kastamonu University, Kastamonu, 37100 Turkey C. Terzioglu, Department of Physics, Abant Izzet Baysal University, Bolu, 14280 Turkey Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    We analyze the energy spectrum of a heterostructure with two particles separated in two crossed wires with parabolic confinement along their axes. We show that the energy spectrum in the limit of extremely strong confinement does not depend on the type of the interaction, and it is similar to the spectrum of a harmonic oscillator. On the contrary, when the confinement is very weak, the two-particle energy spectra for the cases of attraction and repulsion are very different. We present curves for the dependence of the energy levels on the lengths of the wires. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1724-9 Authors G. Elizabeth Escorcia-Salas, Group of Investigation in Condensed Matter Theory, Universidad del Magdalena, A. A. 731, Santa Marta, Colombia I. D. Mikhailov, Universidad Industrial de Santander, A. A. 678, Bucaramanga, Colombia J. Sierra-Ortega, Group of Investigation in Condensed Matter Theory, Universidad del Magdalena, A. A. 731, Santa Marta, Colombia Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In order to enhance levitation performance of the high temperature superconducting (HTS) magnetic levitation (Maglev) vehicle and have more stable and safer operation, levitation forces of YBCO bulk with different movement speeds and operation time at different temperatures are studied. The levitation force is measured using a cryogenic measurement system which has advanced instrumentation. Experimental results show that the levitation force is not only dependent on the temperature but also on the YBCO bulk’s movement speed and operation time. It is found that the effect of YBCO bulk’s movement speed and operation time on the levitation force is larger at higher temperatures, while such effect is smaller at lower temperatures. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1747-2 Authors Hua Jing, Institute of Astronautics and Aeronautics, University of Electronic Science and Technology of China, Chengdu, 610054 P.R. China Suyu Wang, Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, 610031 P.R. China Ming Jiang, Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, 610031 P.R. China Jiasu Wang, Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, 610031 P.R. China Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The magnetic phase diagram of EuFe 2 (As 1− x P x ) 2 was investigated by means of magnetization and muon-spin rotation ( μ SR) studies as a function of chemical (isovalent substitution of As by P) and hydrostatic pressure. The magnetic phase diagrams of the magnetic ordering of the Eu and Fe spins with respect to P content and hydrostatic pressure are determined and discussed. The present investigations reveal that the magnetic coupling between the Eu and the Fe sublattices strongly depends on chemical and hydrostatic pressure. It is found that chemical and hydrostatic pressures have a similar effect on the Eu and Fe magnetic order. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10948-012-1743-6 Authors Z. Guguchia, Physik-Institut der Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland A. Shengelaya, Department of Physics, Tbilisi State University, Chavchavadze 3, 0128 Tbilisi, Georgia A. Maisuradze, Physik-Institut der Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland L. Howald, Physik-Institut der Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland Z. Bukowski, Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-422 Wroclaw, Poland M. Chikovani, Department of Physics, Tbilisi State University, Chavchavadze 3, 0128 Tbilisi, Georgia H. Luetkens, Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland S. Katrych, Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich, Switzerland J. Karpinski, Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich, Switzerland H. Keller, Physik-Institut der Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The surface impedance characteristics of epitaxial YBa 2 Cu 3 O 7− δ films of thickness d f = 75, 150, 300, 600 nm, produced by magnetron thermal co-evaporation onto single crystal MgO substrates was studied using measurement technique based on Ka-band whispering gallery mode (WGM) dielectric resonator (DR) fabricated from single crystal sapphire. Characterization of the unpatterned films was carried out in temperature interval from 20 K to 90 K. It was shown that the effective surface resistance approaches the minimum value for d f 〉300 nm. At the same time, intrinsic impedance properties are practically independent on d f in the studied interval of d f values. The temperature dependence of London penetration depth was estimated experimentally and approximated with the model expressions. Effect of reducing the surface resistance of approximately two times at low temperatures one year later after their manufacture was registered for all films(except the film of 75 nm thickness). The effect may be explained by changes of the film parameters in time after the film light overdoping. Content Type Journal Article Category Original Paper Pages 1-6 DOI 10.1007/s10948-012-1695-x Authors A. A. Barannik, Usikov Institute of Radiophysics and Electronics, National Academy of Sciences of Ukraine, 61085 Kharkiv, Ukraine N. T. Cherpak, Usikov Institute of Radiophysics and Electronics, National Academy of Sciences of Ukraine, 61085 Kharkiv, Ukraine M. S. Kharchenko, Usikov Institute of Radiophysics and Electronics, National Academy of Sciences of Ukraine, 61085 Kharkiv, Ukraine R. Semerad, THEVA Company, Rote-Kreuz-Str. 8, 85737 Ismaning, Germany S. A. Vitusevich, Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    The adsorption of Θ =1/2 monolayer (ML) of S on Au(111) is calculated. The evolution of the positions of adatoms for 800 K, 500 K, 300 K, 150 K, and 1 K is evaluated by using a density functional theory (DFT)-tight binding approach combined with classical molecular dynamics. For this coverage, there is a controversy about the existence of superficial composite AuS or molecular aggregates. We find a configuration in which sulfur atoms form quasi-S 2 superficial molecules with total energy very close to the monoatomic phase, suggesting the coexistence of both configurations at room temperature. We find that the stability of the dimeric phase is due to the increase of the binding energies between sulfurs. In the other phase, the stabilization occurs due to a formation of AuS dimers. At high temperatures ( T 〉300 K) sulfurs have high mobility which allows the migration among different adsorption sites. At low temperatures the mobility decreases and a thermal activation barrier of 25–30 meV can be estimated. Content Type Journal Article Category Original Paper Pages 1-4 DOI 10.1007/s10948-012-1694-y Authors Sandra Carolina Gómez-Carrillo, Departamento de Física, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, S300AOM Santa Fe, Argentina Pablo Guillermo Bolcatto, Departamento de Física, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, S300AOM Santa Fe, Argentina Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    A magnetic diluted nanowire with cylindrical structure described by the Ising model is investigated. Using the effective field theory with a probability distribution technique, the influence of the dilution on the phase diagrams, susceptibility and the hysteresis loops are discussed in detail. Novel features are obtained for the thermal variations of longitudinal susceptibility and longitudinal magnetization. We have investigated the magnetic reversal of the system and have found the existence of triple hysteresis loops patterns, affected by the concentration of magnetic atoms, the temperature, and the exchange interaction between the core and the surface shell. Content Type Journal Article Category Original Paper Pages 1-11 DOI 10.1007/s10948-012-1713-z Authors S. Bouhou, Laboratoire de Physique des Matériaux et Modélisation des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, Physics Department, Faculty of Sciences, University of Moulay Ismail, B.P. 11201, Meknes, Morocco I. Essaoudi, Laboratoire de Physique des Matériaux et Modélisation des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, Physics Department, Faculty of Sciences, University of Moulay Ismail, B.P. 11201, Meknes, Morocco A. Ainane, Laboratoire de Physique des Matériaux et Modélisation des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, Physics Department, Faculty of Sciences, University of Moulay Ismail, B.P. 11201, Meknes, Morocco F. Dujardin, Laboratoire de Physique des Milieux Denses (LPMD), Institut de Chimie, Physique et Matériaux (ICPM), 1 Bd. Arago, 57070 Metz, France R. Ahuja, Condensed Matter Theory Group, Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden M. Saber, Laboratoire de Physique des Matériaux et Modélisation des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, Physics Department, Faculty of Sciences, University of Moulay Ismail, B.P. 11201, Meknes, Morocco Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939

Description:    In this article, we report current–voltage measurements carried out on a Bi 2 Sr 2 CaCu 2 O x whisker in a large temperature range below the critical temperature with and without applied magnetic field. We examine the critical current peak effect and the vortex dynamics at low field. The critical current peak effect consists of the initial increase of the critical current that subsequently decreases as the applied field is increased. For current–voltage measurements, this effect is associated with a change in the current–voltage curves that are typical of the flux flow regime at low fields and resemble flux creep characteristics for higher fields. As a general rule, our observations are consistent with the models that link the peak effect to vortex phase transitions. We calculate the critical current in self-field in the flux flow regime taking into account intervortex forces. We suppose that most vortices are pinned by defects while mobile vortices move through plastic channels between the strongly pinned vortex regions. When an external field is applied, we suggest that the increase in the critical current that is observed is linked to oscillations of the pinned vortices. Content Type Journal Article Category Original Paper Pages 1-8 DOI 10.1007/s10948-012-1730-y Authors Serdar Altin, Fen Edebiyat Fakultesi, Fizik Bolumu, Süperiletkenlik Arastirma Grubu, Inonu Universitesi, 44280 Malatya, Turkey Pierre Bernstein, CRISMAT-ENSICAEN (UMR-CNRS 6508), Boulevard du Maréchal Juin, 14050 Caen, France Journal Journal of Superconductivity and Novel Magnetism Online ISSN 1557-1947 Print ISSN 1557-1939