Interlayer exchange coupling: a comparison of two theoretical concepts

Interlayer exchange coupling (IEC) is calculated for Co/Cu and Ni/Cu(100) multilayers. The calculations are based on density functional theory using two different Green function methods. Results of a supercell formulation with periodically repeated layers are compared to results for bilayers treated as planar perturbations. The coupling energy is obtained employing a frozen potential approximation. It will be shown that the results of both methods are in good agreement concerning the oscillation periods. Slight variations of the amplitude might be caused by additional multiple scattering effects in the superlattice.