ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
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
    Modeling of micromagnetic Barkhausen activity using a stochastic process extension to the theory of hysteresis : 37th Annual conference on magnetism and magnetic materials (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 5830-5832 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Recent work by Bertotti [IEEE Trans. Magn. MAG-24, 621 (1988)] and others has shown that it is possible to model the micromagnetic Barkhausen discontinuities at the coercive point using a two-parameter stochastic model. However, the present formulation of the model is restricted to limited regions of the hysteresis curve over which dM/dH is approximately constant and when dH/dt is held at a constant rate. A natural extension of this model is to take the basic result, in which the level of Barkhausen activity in one time period is related to the activity in the previous time period, and increment it by a small amount which is dependent on the differential permeability. The extension of the model proposed here uses the theory of ferromagnetic hysteresis to determine the differential permeability at any point of the hysteresis loop. The Barkhausen activity is then assumed to vary in proportion to the differential permeability. The resulting model allows the Barkhausen sum of discontinuous changes in magnetization to be modelled around the entire hysteresis loop, leading to an important generalization of the basic model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353541
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    HgCdTe dual-band infrared photodiodes grown by molecular beam epitaxy (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 4620-4622 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the demonstration of an all molecular beam epitaxy HgCdTe bias-selectable dual-band infrared photodetector. The mesa device, an n-p-n three layer HgCdTe heterostructure, was in situ doped with arsenic and indium for p- and n-type doping. The device design is similar to a heterostructure floating base transistor. The feasibility of the two-color bias-switchable detector was demonstrated by obtaining backside illuminated spectrally pure dual-band detection at 77 K. Wavelength cutoff (λco) selection to 5.2 μm with 60% quantum efficiency (QE) was obtained by applying a negative bias of −250 meV, and to λco=7.9 μm with 36% QE by applying a positive bias of 250 meV. The current-voltage characteristics of this device can be described in terms of a simple back-to-back diode model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349099
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The electrical properties of a-Ge/a-SiOx superlattices (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 901-905 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In-plane dc conductivity and ac perpendicular conductivity measurements have been performed on a-Ge/a-SiOx superlattices. The in-plane conductivity data are fitted to a four layer model for each period which allows the density of interface electronic defect states about the Fermi level to be estimated (4×1010 cm−2 per interface). The ac perpendicular conductivity data are successfully modeled and from the fitted parameters it is found that the perpendicular dc conductivity away from a Schottky metal/film region increases above that of a-SiOx when the a-SiOx layers are thinner than 7 nm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349621
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Critical behavior in two reentrant NiMn ferromagnets : 35th annual conference on magnetism and magnetic materials San Diego, California (USA) 29 Oct − 1 Nov 1990 (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 5060-5062 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The real and imaginary components of the low-field dynamic susceptibility of two reentrant NiMn ferromagnets containing 22.5 and 23 at. % Mn have been measured as a function of temperature in static magnetic fields up to 43.3 Oe. The real component χ' exhibits a triple-peaked structure. A critical analysis confirms the highest temperature component of this structure as a manifestation of the critical fluctuations associated with the paramagnetic–ferromagnetic transition. The remaining double-peaked structure is localized in the vicinity of the reentrant transition and is accompanied by a complementary structure in the imaginary component χ‘. A correlation is established between the reentrant susceptibility peaks and the reentrant phase boundaries predicted by vector spin models for bond disordered systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.348147
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Probe diameter and probe–specimen distance dependence in the lateral resolution of a scanning Kelvin probe (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 1673-1679 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The ability of a scanning Kelvin probe (SKP) to resolve lateral differences in specimen surface potential is investigated by two routes. First, electrostatic calculations are used to obtain analytical expressions for the maximum lateral resolution attainable by a "point probe" of negligible physical dimensions, as a function of probe–specimen distance. Second, lateral resolution is measured experimentally by scanning plane-ended cylindrical probes of varying diameters at varying heights across a linear edge, delimiting two electrically continuous coplanar areas of dissimilar metal. Finally the two approaches are combined to obtain a semiempirical relationship between probe diameter, probe–specimen distance, and lateral resolution for plane-ended cylindrical probes. An expression is also developed for the minimum error to be expected in a surface potential measurement when this is associated with a specimen feature exhibiting a diameter comparable with the probe–specimen distance. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1430546
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Symmetry operators and separation of variables for spin-wave equations in oblate spheroidal coordinates (1990)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 31 (1990), S. 1739-1744 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: A family of second-order differential operators that characterize the solution of the massless spin s field equations, obtained via separation of variables in oblate spheroidal coordinates and using a null tetrad is found. The first two members of the family also characterize the separable solutions in the Kerr space-time. It is also shown that these operators are symmetry operators of the field equations in empty space-times whenever the space-time admits a second-order Killing–Yano tensor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.528670
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Teukolsky–Starobinsky identities for arbitrary spin (1989)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 30 (1989), S. 2925-2929 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: The Teukolsky–Starobinsky identities are proven for arbitrary spin s. A pair of covariant equations are given that admit solutions in terms of Teukolsky functions for general s. The method of proof is shown to extend to the general class of space-times considered by Torres del Castillo [J. Math. Phys. 29, 2078 (1988)].
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.528479
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Preisach analysis of two ferromagnetic perovskites: La0.95Mg0.05MnO3 and La0.5Sr0.5CoO3 (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 7248-7250 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Measurements of the major hysteresis loop and of the temperature dependence of the field cooled and zero field cooled moment in applied fields less than the coercive field have been performed on two ferromagnetic perovskites La0.95Mg0.05MnO3 and La0.5Sr0.5CoO3. The data have been analyzed within the framework of a generalized Preisach model which includes thermal fluctuations, critical effects, and a temperature dependent distribution of free energy barriers. The analysis shows that the response functions of the manganese perovskite are dominated by the growth of the anisotropy barriers, while in the cobalt perovskite, thermal fluctuations and barrier growth play a roughly equal role. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1355340
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    FAR-IR/THz radiation from the Jefferson Laboratory, energy recovered linac, free electron laser : Papers from the 12th National Synchrotron Radiation Instrumentation Conference (2002)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 73 (2002), S. 1461-1463 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The free electron laser at Jefferson Laboratory is the first of a new generation of light sources based on a photoinjected energy recovered linac. The present machine has a 40 MeV electron beam and an average current of 5 mA. The electron bunches are extremely short with full width at half maximum values that are in the few hundred femtosecond regime. These electron bunches pass a chicane around the optical cavity, and therefore, emit synchrotron radiation. In the far-IR region, the wavelength of the light being emitted approaches that of the electron bunch length, giving rise to multiparticle coherent enhancement. The result is a broadband spectrum whose average brightness is more than five orders of magnitude higher than can be obtained from conventional incoherent synchrotron IR sources. We will discuss preliminary measurements of this radiation, and applications to spectroscopy and imaging. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1420758
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Midinfrared beamline at the National Synchrotron Light Source port U2B : Proceedings of the 5th international conference on synchrotron radiation instrumentation (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 1643-1645 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new infrared beamline has been developed on a conventional dipole bending magnet port of the vacuum ultraviolet ring at the National Synchrotron Light Source. The port provides approximately 12 mrad horizontal and 8 mrad vertical aperture, which limits the useful spectral range to wavelengths less than 20 μm. Though the total flux across the midinfrared is less than that from a globar source, the calculated brightness is at least two orders of magnitude greater. Also, the synchrotron source delivers light in subnanosecond pulses. The developing experimental programs include studies of hydrogen and other materials at extremely high pressures, and time-resolved studies of infrared sensor materials. The measurement results presented here, characterizing the actual brightness advantage and spectroscopic performance, demonstrate the synchrotron's remarkable advantage for microspectroscopic studies. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1145870
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...