GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 5429-5431 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Theoretical spectra for the magneto-optical Kerr effect in polar geometry have been obtained for four series of L21 Heusler alloys Fe2 YZ and Co2 YZ, with Y=V, Cr, Mn, Fe, Co, Ni and Z=Al or Ga. Selected spectra are presented. Trends are identified in the relation between electronic structure and the polar Kerr angle spectrum for L21. Further it is shown that the large Kerr rotation in the C1b compound PtMnSb cannot be attributed to a few states close to the Fermi level. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 490-496 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The complex dielectric response of strontium barium niobate relaxor ferroelectrics has been studied as a function of orientation and composition. The dielectric response was found to be strongly dependent on orientation, in distinct comparison to the nearly orientation-independent response found for Pb-based perovskite relaxors. Investigations of the temperature dependence of the high-field polarization behavior found that the square-to-slim loop hysteresis transition occurred rapidly with increasing temperature. In addition, no deviations from Curie–Weiss behavior were found, however two distinct linear regions were observed. An anisotropic dielectric glasslike model involving the freezing of heterophase fluctuations is then discussed in reference to the data.
    Type of Medium: Electronic Resource
    Location Call Number Limitation 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. 6781-6785 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Higher binding energies (30–60 meV) in II–VI wide-gap materials result in large exciton densities, making optical transitions due to excitons dominant over free electrons and holes. Optical gain and threshold current densities in ZnCdSe based multiple quantum wire lasers are computed including the effect of strain. It is found that the tensile-strained quantum wires yield lower threshold current densities than compressive strained or unstrained structures. The calculated threshold current density for a defect free tensile-strained ZnCdSe–ZnMgSSe quantum wire laser, realized on an InP substrate, has been computed to be 58 A/cm2. The exciton transitions assist in lowering the threshold current density which is adversely affected by the presence of dislocations and surface states. It is found that the threshold current density would increase to 435 A/cm2 assuming 1017 cm−3 trapping levels due to dislocations and surface states. However, taking into account the exciton transitions, the threshold current density is reduced to 79 A/cm2 when assuming the same trapping level density. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 497-501 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Variable angle spectroscopic ellipsometry (VASE) technique is used to measure the optical constants of InGaAs/GaAs multiple quantum well (MQW) structures for the purpose of designing tunable optical modulators. The VASE measurements also include field-induced changes in index of refraction and absorption. These measured changes in MQWs are in agreement with theoretical computations. In addition, the design and simulated performance of an InGaAs/GaAs MQWs Fabry–Perot modulator using the VASE data is presented. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 6199-6199 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: First principles electronic structure calculations are used to predict the energy dependence of the polar Kerr effect in MnBi, MnSb, and a Mn2BiSb alloy. The compounds all have respectable Kerr angles and thus are potential data storage media. The technique used in this work is a full-potential linearized augmented Slater orbital approach. The Kerr angle is obtained from the conductivity tensor that is calculated, within linear response theory, using the Kubo formula. There are several desirable features in this approach. First, unlike methods based upon muffin-tin potentials, open crystal structures present no problems. Second, since the electronic wave functions are defined over the crystal unit cell rather than over space filling overlapping spheres, difficulties in handling the interstitial part of the required matrix elements are avoided. Finally, the small basis set (25 orbitals per atom) leads to reasonable computational times. Results of these calculations show that the Kerr angle in MnBi is above 1° at 1.6 eV and that its variation over 2–4 eV is linear and decreasing. MnSb shows a smaller rotation, about 0.5°, that is almost constant up to 3 eV and then also decreases linearly. The Kerr rotation of Mn2BiSb is approximately the average of MnBi and MnSb. This work has been supported in part by the Louisiana Quality Education Support Fund under Grant No. LEQSF (1991–1994)-RD-A-30. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 6196-6198 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present theoretical calculations of the magneto-optic polar Kerr effect in bcc iron, fcc cobalt, and hcp cobalt. The Kerr angle and ellipticity are derived from the optical conductivity tensor, which is computed using wave functions obtained from full potential local spin-density electronic structure calculations. Predicted Kerr angles and ellipticities are computed as a function of magnetization direction. In the case of iron, the calculated Kerr spectra are found to be in good agreement with experimental results and previous calculations. However, in the case of cobalt, the results of previous theoretical studies differ significantly. Our results are in close agreement with experiment and with one of these previous theoretical studies. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 7354-7359 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This article presents computation of optical gain and threshold current density in InGaN–AlGaN quantum wire and dot lasers in the presence of dislocations and surface states. The exciton binding energy including the effect of strain induced piezoelectric field is calculated to be 10–80 meV in InGaN–AlGaN quantum wires and dots, depending on the lateral and transverse dimensions. In contrast to the conventional GaAs or InP based quantum wires, these high binding energy results in large exciton densities, making optical transitions due to excitons dominant over free electrons and holes. Optical gain and threshold current density in InGaN–AlGaN based multiple quantum wire and dot lasers are computed including the effect of dislocation-induced traps. The calculated threshold current density Jth for defect free compressive-strained InGaN quantum wire (50 Å×50 Å) and dot (50 Å × 50 Å × 50 Å) lasers, realized on sapphire or SiC substrates, are shown to yield ultralow threshold current density of 233 and 88 A/cm2, respectively. In the presence of dislocations (1×1010 cm−2), the threshold current densities only increase to 924 and 623 A/cm2 for the same wire and dot, when we include the contribution of excitonic transitions. However, the corresponding values increase significantly to 30 838 and 11 647 A/cm2 if the exciton enhancement is not included. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 4656-4660 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A method for detecting surface plasmon resonance with high resolution (∼10−5 degrees or ∼10−8 refractive index units) and fast response time (1 μs) is described. In the method, light is focused through a prism onto a metal film on which molecules to be detected are adsorbed. The total internal reflection of the incident light is collected with a bicell photodetector instead of a single cell or an array of photodetectors that are widely used in previous works. The ratio of the differential signal to the sum signal of the bicell photodetector provides an accurate measurement of shift in surface plasmon resonance angle caused by the adsorption of molecules onto the metal films or by conformational changes in the adsorbed molecules. Using the method, we have studied subtle conformational changes in redox protein, cytochrome c, due to an electron transfer reaction. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 5427-5432 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The electrical transport properties of CoSi2 and Co(SixGe1−x)2 thin films formed by solid state interaction and co-evaporation in the range of 4–300 K were studied. The Hall effect data indicate a hole carrier conduction in all samples. The rapid thermal annealed CoSi2 exhibits a typical metallic conduction with a residual resistivity of 3.3-μΩ-cm and room-temperature (RT) resistivity of 15 μΩ cm. The co-evaporated CoSi2 and Co(Si0.9Ge0.1)2 films after low temperature annealing up to 250 °C show a low resistivity of 70–80 μΩ cm at RT and change little down to 4 K. The hole carrier density of all the samples studied has values close to 2–3×1022 cm−3, while the carrier Hall mobility has large differences.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: YBa2Cu3O7−x superconducting thin films with a critical current density of 2.3×106 A/cm2 at 77.7 K and 0 T were prepared by a metalorganic chemical vapor deposition process. The films were formed in situ on LaAlO3 at a substrate temperature of 730 °C in 2 Torr partial pressure of N2O. Resistivity and magnetic susceptibility measurements of the as-deposited films show a sharp superconducting transition temperature of 89 K with a narrow width of less than 1 K. Critical current densities were measured by the dc transport method with a patterned bridge of 120 μm×40 μm. Both x-ray diffraction and high-resolution electron microscopy measurements indicate that films grew epitaxially with the c axis perpendicular to the surface of the substrate.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...