Conductivity and magnetoresistance of magnetic multilayered structures

Abstract

We consider multilayered structures consisting of magnetic and nonmagnetic metals. We derive analytic expressions for the conductivities by treating the scattering at the interfaces between layers in the same way as that throughout the layers (bulk). The application of an external magnetic field reorients the magnetization in the magnetic layers, which in turn alter the mean free path of the conduction electrons. This is the origin of the giant magnetoresistance seen in iron-chromium (Fe/Cr) superlattices. We present analytic results on the magnetoresistance in limiting cases where either the mean free path is much greater or less than the layer thickness, as well as numerical results for the realistic situation found in Fe/Cr superlattices when they are comparable.