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.
@article{arxiv.0906.0594,
title = {Magnetodielectric Coupling in Nonmagnetic Au/GaAs:Si Schottky Barriers},
author = {S. Tongay and A. F. Hebard and Y. Hikita and H. Y. Hwang},
journal= {arXiv preprint arXiv:0906.0594},
year = {2015}
}