RUDERMAN-KITTEL THEORY OF OSCILLATORY INTERLAYER EXCHANGE COUPLING

We present a Ruderman-Kittel approach to the problem of oscillatory exchange coupling between ferromagnetic layers separated by a nonmagnetic metal spacer. This model provides a very simple explanation for the occurrence of long periods as well as multiperiodic oscillations, and is valid for arbitrary crystal structure and Fermi surface. The role of defects, such as misfit dislocations and interfacial roughness, is discussed.