ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • American Institute of Physics (AIP)  (11)
  • Geological Society of America (GSA)  (3)
  • Institute of Physics (IOP)  (3)
  • Hindawi
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 2038-2038 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 2945-2949 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this work the AlCo intermetallic compound has been prepared by high-energy ball milling of Co and Al powder mixtures with the composition of Co-50 at.% Al, Co-71.4 at.% Al, Co-76.5 at.% Al, and Co-81.8 at.% Al, respectively. X-ray diffraction and transmission electron microscopy analysis of powders milled for different times proved that the AlCo phase formed directly during milling of the powder mixture of the former three compositions. In the Co-81.8 at.% Al powder mixture the amorphous phase was first formed and then crystallized to the AlCo phase. The result of energy dispersion x ray showed that the composition of AlCo phase formed during milling of the above four compositions is in agreement with that of the powder mixture, although their crystal structure is that of the AlCo intermetallic compound. The results indicate that the solubility range of intermetallic compound during mechanical alloying processes can be greatly enhanced by high-energy ball milling. The enhancement of solubility is discussed based on the structural features of nanocrystals.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 1392-1395 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: To study the size effects in ferroelectric thin film, we measured the optical transmittance and Raman spectra in BaTiO3 thin films deposited by the rf-magnetron sputtering technique on fused quartz and (111) Si substrates. A variation in the energy gap and Raman peaks with film thickness and grain size was observed and the possible origin was analyzed. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 7514-7518 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Al-Co powder mixtures of several different compositions are mechanically alloyed by high-energy ball milling (HEBM) and then annealed. The structure analysis of x-ray diffraction and transmission electron microscopy revealed that the metastable phase obtained by HEBM decomposes to several stable phases during heating. The formed phases include decagonal quasicrystal (DQC), a new approximant of DQC, and several other known crystal phases that appear to depend on the composition of powder mixture. Convergent-beam electron-diffraction analysis has also been taken to determine the space group of the new phase. Finally, the structural relation between the known Al3Co and the new phase is also discussed in view of the crystal symmetry.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 5386-5393 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In order to understand the radiative recombination mechanisms in silicon oxides, photoluminescence properties (PL) of H-rich amorphous silicon oxide thin films grown in a dual-plasma chemical vapor deposition reactor have been related to a number of stoichiometry and structure characterizations (x-ray photoelectron spectroscopy, vibrational spectroscopy, and gas evolution studies). The visible photoluminescence at room temperature from a-SiOx:H matrixes with different compositions, including different bonding environments for H atoms, has been studied in the as-deposited and annealed states up to 900 °C. Three commonly reported PL bands centered around 1.7, 2.1, and 2.9 eV have been detected from the same type of a-SiOx:H material, only by varying the oxygen content (x = 1.35, 1.65, and 2). Temperature quenching experiments are crucial to distinguish the 1.7 eV band, fully consistent with bandtail-to-bandtail recombination, from the radiative defect luminescence mechanisms attributed either to defects related to Si–OH groups (2.9 eV) or to oxygen-vacancy defects (2.1 eV). In the latter case, a red-shift of the PL peak energy as a function of annealing temperature is probably attributed to some matrix-induced strain effect. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2016-06-21
    Description: We report on a comparative study of efficiency droop in polar and non-polar InGaN quantum well structures at T = 10 K. To ensure that the experiments were carried out with identical carrier densities for any particular excitation power density, we used laser pulses of duration ∼100 fs at a repetition rate of 400 kHz. For both types of structures, efficiency droop was observed to occur for carrier densities of above 7 × 10 11  cm −2  pulse −1 per quantum well; also both structures exhibited similar spectral broadening in the droop regime. These results show that efficiency droop is intrinsic in InGaN quantum wells, whether polar or non-polar, and is a function, specifically, of carrier density.
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2015-04-14
    Description: We have studied the ultrafast changes of electronic states in bulk ZnO upon intense hard x-ray excitation from a free electron laser. By monitoring the transient anisotropy induced in an optical probe beam, we observe a delayed breaking of the initial c-plane symmetry of the crystal that lasts for several picoseconds. Interaction with the intense x-ray pulses modifies the electronic state filling in a manner inconsistent with a simple increase in electronic temperature. These results may indicate a way to use intense ultrashort x-ray pulses to investigate high-energy carrier dynamics and to control certain properties of solid-state materials.
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2016-08-23
    Description: Ediacaran Doushantuo (Formation) embryo-like fossils (EDEFs, ca. 600 Ma) from South China display cellular and sub-cellular structures and provide a unique window on the early evolution of multicellular eukaryotes. But there have been widely disparate interpretations of these fossils. Here we report new fossil embryo-like forms from the Doushantuo phosphorite that exhibit a meroblastic cleavage pattern. Our results from high-resolution propagation phase contrast–synchrotron radiation X-ray microtomography (PPC-SRµCT) demonstrate that these fossils preserve features directly comparable to those of modern meroblastic animal embryos that utilize discoidal cleavage. Given that discoidal-type meroblastic cleavage occurs only in metazoans, the phylogenetic positions of these fossils probably fall into the animal branch of the holozoan tree. Meroblastic as well as holoblastic cleavage forms were thus present by ca. 600 Ma, substantiating the conclusion derived from molecular clock estimates that a variety of metazoan lineages had evolved by the mid-Ediacaran after the termination of the Marinoan glaciation, if not earlier.
    Print ISSN: 0091-7613
    Electronic ISSN: 1943-2682
    Topics: Geosciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2015-12-03
    Description: Bubbles induced by blast waves or shocks are speculated to be the major cause of damages in biological cells in mild traumatic brain injuries. Microbubble collapse was found to induce noticeable cell detachment from the cell substrate, changes in focal adhesion and biomechanics. To better understand the bubble mechanism, we would like to construct a system, which allows us to clearly differentiate the impact of bubbles from that of shocks. Such a generator needs to be low profile in order to place under a microscope. A piezoelectric transducer system was designed to meet the need. The system uses either a flat or a spherical focusing piezoelectric transducer to produce microbubbles in a cuvette loaded with cell-culture medium. The transducer is placed on the side of the cuvette with its axis lining horizontally. A cover slip is placed on the top of the cuvette. The impact of the waves to the cells is minimized as the cover slip is parallel to the direction of the wave. Only bubbles from the medium reach the cover slip and interact with cells. The effect of bubbles therefore can be separated that of pressure waves. The bubbles collected on a cover slip range in size from 100 μm to 10 μm in radius, but the dominant size is 20-30 μm.
    Print ISSN: 0034-6748
    Electronic ISSN: 1089-7623
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2014-10-02
    Description: Mixed-anion, GaAs 1-y Sb y metamorphic materials with a wide range of antimony (Sb) compositions extending from 15% to 62%, were grown by solid source molecular beam epitaxy (MBE) on GaAs substrates. The impact of different growth parameters on the Sb composition in GaAs 1-y Sb y materials was systemically investigated. The Sb composition was well-controlled by carefully optimizing the As/Ga ratio, the Sb/Ga ratio, and the substrate temperature during the MBE growth process. High-resolution x-ray diffraction demonstrated a quasi-complete strain relaxation within each composition of GaAs 1-y Sb y . Atomic force microscopy exhibited smooth surface morphologies across the wide range of Sb compositions in the GaAs 1-y Sb y structures. Selected high-κ dielectric materials, Al 2 O 3 , HfO 2 , and Ta 2 O 5 were deposited using atomic layer deposition on the GaAs 0.38 Sb 0.62 material, and their respective band alignment properties were investigated by x-ray photoelectron spectroscopy (XPS). Detailed XPS analysis revealed a valence band offset of 〉2 eV for all three dielectric materials on GaAs 0.38 Sb 0.62 , indicating the potential of utilizing these dielectrics on GaAs 0.38 Sb 0.62 for p-type metal-oxide-semiconductor (MOS) applications. Moreover, both Al 2 O 3 and HfO 2 showed a conduction band offset of 〉2 eV on GaAs 0.38 Sb 0.62 , suggesting these two dielectrics can also be used for n-type MOS applications. The well-controlled Sb composition in several GaAs 1-y Sb y material systems and the detailed band alignment analysis of multiple high-κ dielectric materials on a fixed Sb composition, GaAs 0.38 Sb 0.62 , provides a pathway to utilize GaAs 1-y Sb y materials in future microelectronic and optoelectronic applications.
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...