Current-induced magnetization reversal mechanisms of pseudospin valves with perpendicular anisotropy

Abstract

We present a numerical simulation of current-induced magnetization switching (CIMS) in pseudospin-valve (PSV) structures exhibiting perpendicular anisotropy. The PSV structures consist of a reference layer of Co/Pt and Co/Ni multilayers and a free layer composed of Co/Ni multilayers. The spin torque induced by the passage of a spin-polarized current is modeled by means of a modified Landau-Lifshitz-Gilbert equation, which incorporates two additional spin-torque terms. Numerical micromagnetic simulations of the magnetization switching process predict a critical current density of the order of 107 A cm2, a value consistent with available experimental results. In addition, we investigate the influence of the current sweep rate and the ratio of the in-plane and out-of-plane torque coefficients on the stability of the magnetization switching process. Our analysis provides a useful guide for optimal utilization of the CIMS effect in perpendicularly magnetized multilayers, for use in prospective spintronic applications. © 2007 American Institute of Physics.