Interlayer exchange coupling and interface reflectivities in Fe/Cu, Co/Cu and Ni/Cu(001) layers

We present ab initio calculations for the interlayer exchange coupling of FCC Fe, Co and Ni layers in Cu (0 0 1) which have been performed by a KKR-Green's function method for planar defects. The calculations show strong differences in the amplitudes for the short and long oscillation periods, which in a first approximation can be understood from the bulk band structures of Fe, Co and Ni. We discuss results for the quantum well states in the Cu spacer layers and their relation to interlayer coupling. We investigate in detail the effect of the finite thickness of the magnetic layers and present calculations for the reflectivity of a Cu Blochwave at a magnetic layer of finite thickness. We discuss the temperature dependence of the coupling and the transition from finite-to-infinite layer thickness.