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Open Access. Powered by Scholars. Published by Universities.®

1994

The University of San Francisco

Articles 1 - 3 of 3

Full-Text Articles in Physics

Scaling Of Voltage-Current Characteristics Of Thin-Film Y-Ba-Cu-0 At Low Magnetic Fields, Brandon R. Brown Mar 1994

Scaling Of Voltage-Current Characteristics Of Thin-Film Y-Ba-Cu-0 At Low Magnetic Fields, Brandon R. Brown

Physics and Astronomy

We have measured voltage-current characteristics for YBa2Cu3O7 thin films in magnetic fields from 5 T to ambient, including some in the millitesla range. In all cases, the resistivity-current density isotherms can be separated into two classes: those which exhibit upward curbature, and have constant resistivity at low currents, and those which exhibit downward curvature at all currents. These two classes of isotherms are separated by a field-dependent temperture Tg. For each field, the isotherms scale in a manner consistent with a three dimensional vortex-liquid to vortex-glass phase transition. The region that can be scaled is several kelving at 5 T ...


Theory Of Magnetotransport In Inhomogeneous Magnetic Structures, Horacio E. Camblong Jan 1994

Theory Of Magnetotransport In Inhomogeneous Magnetic Structures, Horacio E. Camblong

Physics and Astronomy

The origin of the giant magnetoresistance of magnetic multilayers and magnetic granular solids is investigated through a unified spin‐dependent linear transport theory, in which the primary source of electrical resistivity is short‐range scattering by impurities in the different magnetic or nonmagnetic regions and at the interfaces. Our theory predicts that magnetotransport in granular solids is similar to that for currents perpendicular to the plane of the layers in multilayers in that their magnetoresistance is independent of the average distance between adjacent magnetic regions.


Effective Internal Fields And Magnetization Buildup For Magnetotransport In Magnetic Multilayered Structures, Horacio E. Camblong Jan 1994

Effective Internal Fields And Magnetization Buildup For Magnetotransport In Magnetic Multilayered Structures, Horacio E. Camblong

Physics and Astronomy

Starting with the Kubo formula for electric conductivity we derive a set of equations that define the spin diffusion that is present when current is driven through inhomogeneous magnetic media. We show the spin accumulation, or nonequilibrium magnetization, attendant to charge transport through regions of inhomogeneous magnetization is governed by the same equations found in a thermodynamic approach to magnetoelectric transport.