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

The influence of the thin Au capping on the Cu wire for the spin current in a lateral spin-valve structure was studied in this paper. The lateral spin-valve structure used consists of two Ni-Fe wires bridged by a nonmagnetic metal wire. Two kinds of nonmagnetic metal wires were used: a single Cu wire and Cu wire covered with Au layer. From the residual resistivity ratio of the wires, it was observed that the double-layered wire was more electrically conductive due to the Au capping layer than the single-layered wire because the capping layer prevents oxidation of the Cu surface. Large spin accumulation was obtained from Cu/Au spin valve than from single-layered Cu one.