(Key Laboratory of Energy Materials and Devices (Liaoning Province), Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116000, China)
The direct and inverse spin Hall effect is the key effect for spin-charge conversion in spintronics, which plays a vital role in the generation and detection of pure spin currents. It is a core issue to develop and explore materials with high spin-charge conversion efficiency. Here, we demonstrate the inverse spin Hall effect in a conductive bismuth oxide. The bismuth oxide thin films with different thicknesses were prepared from a sintered bismuth oxide target by an rf-sputtering system. Then, permalloy/bismuth oxide bilayer spin pumping devices were developed, with which voltage signals corresponding to the inverse spin Hall effect were confirmed by the spin pumping technique. Furthermore, by systematical studying of bismuth-oxide thickness dependence of those spin Hall voltages, the spin Hall angle and spin diffusion length were quantitatively estimated. Our results propose a novel system with an observable inverse spin Hall effect, which expands the possibility of spintronic materials and guides a new path for the development of spin-based devices.