Giant spin Hall effect and magnetotransport in a Ta/CoFeB/MgO layered structure: A temperature dependence study

Using an optimized fabrication and magnetic thermal annealing process, we have obtained a high quality beta-Ta/CoFeB/MgO layered structure with strong spin-orbit coupling. We have studied electron transport, magnetotransport, and magnetic properties of this system over a wide temperature range between 5 and 300 K. We present the results of resistivity, magnetization, giant spin Hall effect (GSHE), perpendicular magnetic anisotropy, and magnetic switching phase diagram. beta-Ta exhibits a large spin Hall angle of 0.14, and shows evidence of spin Hall angle's scaling with resistivity quadratically. The optimized beta-Ta/CoFeB/MgO system displays the lowest switching current density among similar systems. Our comprehensive study will benefit applications of GSHE in spintronics.