Inverse giant magnetoresistance due to spin‐dependent bulk scattering in Fe_1–xCr_x/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. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Mechanism of Inverse Magnetoresistance in High-\(T_{a}\) Annealed MnNi/Co/Ag(Cu)/Py Spin Valves

“…These can be confirmed by Refs. [7][8][9][10][11][12][13][14][15][16][17]. Therefore, it is perfectly reasonable to assume that α Py > 1.…”

“…In these cases, the GMR effect is called the inverse magnetoresistance (IMR). The IMR effect has been observed in the magnetic multi-layer systems with various types of structures [7][8][9][10][11][12][13][14][15][16][17]. The mechanism by which the IMR effect is caused in these structures was primarily based on modulating the spin-dependent conductivity of one of the two FM layers, hence, inverting the spin state density (SSD) at the Fermi level in that FM layer [7][8][9][10][11][12][13].…”