Micromagnetic simulations of nanosecond magnetization reversal processes in magnetic nanopillar

In this paper we study by means of the spin torque model the fast switching behavior of the Co(20nm)∕Cu(5nm)∕Co(2.5nm) magnetic multilayers of two different cross sections: ellipse (130×70nm2) and ellipse (130×40nm2). Simulations have been performed at zero and room (300K) temperatures, these point out that the magnetization inversion occurs by nucleation processes in three main steps, for both structures. In particular, for zero temperature the third step of the switching depends on the value of the spin-polarized current. Furthermore, for all of the simulated currents the switching processes are thermally activated and smoother with respect to zero temperature.