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 lambda(s) and the spin injection polarization P at the Co/Cu interface. The value of lambda(s) is 200 +/- 20 nm at 10 K and >= 110 nm at 300 K, 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.(c) 2006 American Institute of Physics.