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arXiv · 0906.0594

Magnetodielectric Coupling in Nonmagnetic Au/GaAs:Si Schottky Barriers

S. Tongay·A. F. Hebard·Y. Hikita·H. Y. Hwang
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Abstract

We report on a heretofore unnoted giant negative magnetocapacitance (>20%) in non-magnetic Au/GaAs:Si Schottky barriers that we attribute to a magnetic field in-duced increase in the binding energy of the shallow donor Si impurity atoms. Depletion capacitance (Cdep) dispersion identifies the impurity ionization and capture processes that give rise to a magnetic field dependent density of ionized impurities. Internal photoemission experiments confirm that the large field-induced shifts in the built-in potential, inferred from 1/Cdep^2 vs voltage measurements, are not due to a field-dependent Schottky barrier height, thus requiring a modification of the abrupt junction approximation that accounts for the observed magnetodielectric coupling.

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S. Tongay, A. F. Hebard, Y. Hikita, H. Y. Hwang. 2009-06-02. Magnetodielectric Coupling in Nonmagnetic Au/GaAs:Si Schottky Barriers. https://doi.org/10.1103/physrevb.80.205324

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