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

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.