Theory of anisotropy in strained superlattices

Expressions for the magnetic anisotropy energy of strained fcc, bcc, and simple cubic superlattices are obtained for the (100), (011), and (111) orientations. The theory is based on summing pair interactions using the potential (M⋅R)2, where M is the magnetization and R is the vector connecting the two atoms. The theory is shown to predict the orientation independence of the interface anisotropy in a system of Co/Pd superlattices, in agreement with experiment and detailed electronic structure calculation.