Current-induced magnetization switching in pseudo-spin-valve multilayers with and without a Ru capping layer

Abstract

We analyze the spin-current transport in a Co/Cu/Co pseudo-spin-valve (PSV) structure, with and without a Ru cap layer. The resultant spin torque in the PSV and the critical current for switching are evaluated by considering the absorbed transverse spin current at the interfacial zones, spin-dependent transmission and the reflection probabilities across the interfaces, and the spin-diffusion process within the Cu spacer layer. The presence of a Ru cap layer leads to a reduction of the critical current density (by a factor of 1.5), in close agreement with experimental data. Based on our model, several methods are suggested to obtain further reduction in the critical current density, necessary for future applications in spintronic devices. © 2005 The American Physical Society.