Thermal stability of the spin injection in Co/Ag/Co lateral spin valves**Project supported by the National Natural Science Foundation of China (Grant Nos. 11304381 and 11374244), the Research Funds of Renmin University of China (Grant No. 17XNLF02), the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No. 201443), and the Natural Science Foundation of Fujian Province of

Abstract

Spin injection, spin diffusion, and spin detection are investigated in Co/Ag/Co lateral spin valves at room temperature. Clear spin accumulation signals are detected by the non-local measurement. By fitting the results to the one-dimensional diffusion equation, ∼8.6% spin polarization of the Co/Ag interface and ∼ 180 nm spin diffusion length in Ag are obtained. Thermal treatment results show that the spin accumulation signal drastically decreases after 100 °C annealing, and disappears under 200 °C annealing. Our results demonstrate that, compared to the spin diffusion length, the decrease and the disappearance of the spin accumulation signal are mainly dominated by the variation of the interfacial spin polarization of the Co/Ag interface.