Inverse giant magnetoresistance due to spin-dependent bulk scattering in Fe1-xCrx/Cu/Co

Abstract

Inverse giant magnetoresistance (IGMR) can be observed in multilayers with alternating two ferromagnetic layers F1 and F2 possessing opposite spin scattering asymmetries. We report here the observation of inverse current-in-plane giant magnetoresistance (CIP-IGMR) in Fe1-xCrx/Cu/Co spin-valve systems with varying Cr concentration and FeCr-layer thickness. The highest magnitude of IGMR, -0.45 %, has been achieved in the sample doped with 35 at. % Cr. It is shown that the proper substitution of Cr for Fe can alter spin-dependent scattering in the Fe layer, causing the inversion of the bulk spin scattering asymmetry coefficient therefore resulting in CIP-IGMR. The GMR has a dominant contribution to the observed inverse MR, rather than the anisotropic magnetoresistance (AMR) component. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.