Spin relaxation characteristics in Ag nanowire covered with various oxides

摘要

We have studied spin relaxation characteristics in a Ag nanowire covered withvarious oxide layers of Bi2O3, Al2O3, HfO2, MgO or AgOx by using non-local spinvalve structures. The spin-flip probability, a ratio of momentum relaxationtime to spin relaxation time at 10 K, exhibits a gradual increase with anatomic number of the oxide constituent elements, Mg, Al, Ag and Hf.Surprisingly the Bi2O3 capping was found to increase the probability by anorder of magnitude compared with other oxide layers. This finding suggests thepresence of an additional spin relaxation mechanism such as Rashba effect atthe Ag/Bi2O3 interface, which cannot be explained by the simple Elliott-Yafetmechanism via phonon, impurity and surface scatterings. The Ag/Bi2O3 interfacemay provide functionality as a spin to charge interconversion layer.