A. Chaiken, C.J. Gutierrez, J.J. Krebs, and G.A. Prinz, Code 6345, Naval Research Laboratory, Washington, DC 20375
The magnitude of the giant or spin-valve magnetoresistance in ferromagnet/paramagnet/ferromagnet sandwiches depends on the choice of ferromagnet. In this study, the dependence of the giant magnetoresistance on the composition of the alloy layer in a series of Fe/Ag/CoxFe1-x sandwiches has been varied in order to get some insight into the fundamental origin of the effect. The CoxFe1-x alloy layers can be grown in the bcc phase throughout the range 0 < x < 1 using molecular beam epitaxy. The anisotropic magnetoresistance of these sandwiches shows a simple linear dependence on x, the Co fraction, but the giant magnetoresistance has a non-monotonic composition dependence.