COMPOSITION DEPENDENCE OF GIANT MAGNETORESISTANCE IN FE AG/COXFE1-X SANDWICHES/

The magnitude of the giant or spin-valve magnetoresistance in ferromag net/paramagnet/ferromagnet sandwiches depends on the choice of ferroma gnet. In this study, the dependence of the giant magnetoresistance on the composition of the alloy layer in a series of Fe/Ag/CoxFe1-x sandw iches has been varied in order to get some insight into the fundamenta l origin of the effect. The CoxFe1-x alloy layers can be grown in the bcc phase throughout the range 0 less-than-or-equal-to x less-than-or- equal-to 1 using molecular beam epitaxy. The anisotropic magnetoresist ance of these sandwiches shows a simple linear dependence on x, the Co fraction, but the giant magnetoresistance has a non-monotonic composi tion dependence.