Spin–orbit torque induced magnetization switching in the W/CoFeB/Zr/MgO multilayers with high thermal stability

Abstract

We demonstrate the spin–orbit torque (SOT) induced perpendicular magnetization switching in an annealed W/CoFeB/Zr/MgO multilayer with high thermal stability. It is found that the thermal stability factor can reach 79 after annealing at 540 °C. With an increase in the annealing temperature, the absolute damping-like efficiency almost keeps a high constant value (about 0.3). The tungsten in the W/CoFeB/Zr/MgO multilayer could convert from the high resistive β-W to a mediate resistive amorphous-like structure. Therefore, the absolute spin Hall conductance increases from 765 of β-W to 1420 (ℏ/e)(Ω cm)−1 of the amorphous-like tungsten. These results pave a realistic way for the practical application of tungsten in the SOT-based spintronics devices with high thermal stability and SOT efficiency.