Enhanced spin injection polarization in Co∕Cu∕Co nonlocal lateral spin valves

Nonlocal spin injection is demonstrated in Co∕Cu∕Co lateral spin valves. Measurement of a series of structures with varying Cu length between the Co electrodes permits a direct determination of both the Cu spin diffusion length λs and the spin injection polarization P at the Co∕Cu interface. The value of λs is 200±20nm at 10K and ⩾110nm at 300K, which is shorter than previously reported, due to the possible presence of impurities in the Cu. However, the value of P is >7%, which is improved compared with previous reports of 2%, which is attributed to a higher interfacial quality.