Domain Wall Motion In Ultrathin Co70fe30/Pd Multilayer Nanowires With Perpendicular Anisotropy

We report the investigation of spin polarized current induced domain wall (DW) displacement in the perpendicularly magnetized nanowires patterned on ultrathin CoFe/Pd multilayer films by anomalous Hall-effect measurement. We find that DWs can be driven to propagate in the nanowire by the threshold current density (J(th)) as low as 5.2 x 10(10) A/m(2) under a bias field H=115 Oe. The spin-torque efficiency epsilon-(1.68 +/- 0.09) x 10(-14) T.m(2)/A is derived by measuring the effective field (H-J) generated by the pulsed current as well as through the dependency of Jth on H from the DW depinning field experiment. Our result indicates that the current induced DW motion is essentially dominated by the non-adiabatic spin transfer torque effect and the non-adiabaticity factor beta is estimated to be as high as 0.96 +/- 0.04. (C) 2016 AIP Publishing LLC.