A study of spin relaxation on spin transfer switching of a noncollinear magnetic multilayer structure

Abstract

We study the spin relaxation effects in spacer and free layers on spin torque of a current-perpendicular-to-plane (CPP) magnetic multilayer structure with noncollinear magnetization. We apply a generalized spin drift-diffusion model based on previous models by Zhang, Levy, and Fert, which accounts for both longitudinal and transverse components of spin accumulation and a spin current in a noncollinear system. The transverse spin accumulation and the areal resistance of a typical Co-Cu-Co pseudo-spin-valve are calculated as functions of angular deviation between the free and fixed Co magnetizations in the presence of an additional capping layer of Au. It was found that a long spin diffusion length in the spacer layer and a short transverse spin diffusion length in the free layer play a critical role in producing a high spin transfer torque within the free layer. © 2008 American Institute of Physics.