Temperature dependence of current-induced magnetic domain wall motion in an asymmetric Co/Ni nanowire

Abstract

We have investigated the temperature dependence of current-induced magnetic domain wall (DW) motion in a Co/Ni nanowire, where the spin Hall torque is responsible for the DW motion. The threshold current density (J(th)) for DW motion is found to be dependent on the temperature T and the depinning magnetic field H-dep, which is different from the symmetric Co/Ni system where J(th) is insensitive to T and H-dep. This result indicates that an extrinsic pinning governs the DW motion when it is driven by the spin Hall torque. Our work therefore suggests that reducing the extrinsic pinning is a key for achieving a low-power-consumption device. (C) 2015 The Japan Society of Applied Physics