We present a study of the proximity effect between a ferromagnet and a paramagnetic metal of varying disorder. Thin beryllium films are deposited onto a 5 nm-thick layer of the ferromagnetic insulator EuS. This bilayer arrangement induces an exchange field, Hex, of a few tesla in low resistance Be films with sheet resistance R≪RQ, where RQ=h/e2 is the quantum resistance. We show that Hex survives in very high resistance films and, in fact, appears to be relatively insensitive to the Be disorder. We exploit this fact to produce a giant low-field magnetoresistance in the correlated insulator phase of Be films with R≫RQ.
@article{arxiv.1211.1663,
title = {Exchange Field-Mediated Magnetoresistance in the Correlated Insulator Phase of Be Films},
author = {T. J Liu and J. C. Prestigiacomo and Y. M. Xiong and P. W. Adams},
journal= {arXiv preprint arXiv:1211.1663},
year = {2012}
}