Influence of Au capping Layer on spin accumulation in a lateral spin-valve structure

We investigate the influence of Au capping layer on the spin accumulation in a lateral spin valve consisting of Permalloy and Cu wires. The nonlocal spin valve measurements show that the Au capping significantly suppresses the spin accumulation in the Cu wire, although it improves the electrical conductivity. This is understood as a result of the small spin-flip resistance of Au whereby absorbed spins are successively flipped.