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 β-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 5K and 300 K. We present the results of resistivity, magnetization, Giant Spin Hall Effect (GSHE), perpendicular magnetic anisotropy, and magnetic switching phase diagram. β-Ta exhibits a large spin Hall angle of 0.14, and shows evidence of spin Hall angle’s scaling with resistivity quadratically. The optimized β-Ta/CoFeB/MgO system displays the lowest switching current density among similar systems. Our comprehensive study will benefit applications of GSHE in spintronics. PACS numbers: 75.70.Tj, 72.25.Ba, 72.25.Mk, 72.15.Gd, 75.30.Gw, 75.47.Np