In-plane current-induced magnetization reversal of Pd/CoZr/MgO magnetic multilayers

High critical current density ($> 10^{6}$ A/cm$^{2})$ is one of major obstacles to realize practical applications of the current-driven magnetization reversal devices. In this work, we successfully prepared Pd/CoZr(3.5 nm)/MgO thin films with large perpendicular magnetic anisotropy and demonstrated a way of reducing the critical current density with a low out-of-plane magnetic field in the Pd/CoZr/MgO stack. Under the assistance of an out-of-plane magnetic field, the magnetization can be fully reversed with a current density of about 10$^{4}$ A/cm$^{2}$. The magnetization reversal is attributed to the combined effect of the out-of-plane magnetic field and the current-induced spin-orbital torque. It is found that the current-driven magnetization reversal is highly relevant to the temperature owing to the varied spin-orbital torque, and the current-driven magnetization reversal will be more efficient in low-temperature range, while the magnetic field is helpful for the magnetization reversal in high-temperature range.