Europhys. Lett.
Volume 63, Number 6, September 2003
Page(s) 874 - 880
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 November 2003
DOI: 10.1209/epl/i2003-00606-0
Europhys. Lett., 63 (6) , pp. 874-880 (2003)

Inverse giant magnetoresistance due to spin-dependent interface scattering in $\chem{Fe/Cr/Au/Co}$

M. Buchmeier, R. Schreiber, D. E. Bürgler and P. Grünberg

Institut für Festkörperforschung, Forschungszentrum Jülich GmbH D-52425 Jülich, Germany

(Received 9 December 2002; accepted in final form 10 July 2003)

We have found an inverse current-in-plane giant magnetoresistance (CIP-GMR) effect in epitaxial $\chem{Fe/Cr/Au/Co}$ samples grown by molecular-beam epitaxy. The $\chem{Fe}$ and $\chem{Co}$ magnetic layers are decoupled, and antiparallel alignment is achieved by the different coercivities of the $\chem{Fe}$ and $\chem{Co}$ layers. The inverse GMR ratio is approximately one order of magnitude smaller than i) the normal GMR ratio of $\chem{Fe/Cr/Co}$ or comparable epitaxial $\chem{Fe/Cr/Fe}$ samples, and ii) the simultaneously observed anisotropic magnetoresistance (AMR). The comparison with $\chem{Fe/Cr/Co}$ and $\chem{Fe/Au/Co}$ systems, which both show a normal GMR effect, demonstrates that the inversion of the GMR effect is solely induced by modifying the non-magnetic spacer layer. Therefore, these experiments give strong evidence that interface scattering significantly contributes to the CIP-GMR. This conclusion is further supported by an analysis in terms of interface scattering spin asymmetries.

73.40.-c - Electronic transport in interface structures.
75.47.De - Giant magnetoresistance.
75.70.Cn - Magnetic properties of interfaces (multilayers, superlattices, heterostructures).

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