Orientational and thickness dependence of interfacial magnetocrystalline anisotropy in Co/Cu superlattices

The interface magnetocrystalline anisotropy (MCA) of (0 0 1), (1 1 0) and (1 1 1) oriented Co/Cu_n superlattices (n ≤ 5) was investigated by means of the full potential linearized augmented-plane-wave (FLAPW) method. The results show a marked dependence of the interface MCA on both the orientation and the thickness of the Cu layer. For (0 0 1) oriented superlattices, the small value of the interface MCA with one Cu layer increases significantly as more Cu layers are added. In contrast, the interface MCA of (1 1 0) and (1 1 1) oriented superlattices are not sensitive to the number of Cu layers. The interface MCA is large and positive in the (0 0 1) orientation for n = 3 and 5 and slightly positive in the (1 1 1) orientation for n = 2 and 5, corresponding to a perpendicular easy axis while the (1 1 O) oriented superlattices show in-plane easy axis.