Spin-dependent scattering from correlated impurities at interfaces

The single-cluster coherent potential approximation (CPA) including off-diagonal coherent potential is applied to interdiffusional interfaces with correlated impurities. It is assumed that atoms on two monolayers nearest the interface may exchange between the two monolayers and within each monolayer so that there exist four kinds of atomic configurations in a two-atom cluster. In the presence of correlation the interfacial scattering rate is found to depend not only on the diagonal part of the coherent potential, but also on the off-diagonal part. Calculated results show that the correlation produces interfacial scattering which is more strongly spin dependent than the scattering in the bulk.