Thin ferromagnetic films on nonmagnetic metallic substrates: A model calculation

We report a model calculation of the electronic and magnetic properties of a single layer of ferromagnetic material deposited on a nonmagnetic metallic substrate. A tight-binding Hamiltonian with a Hubbard-type interaction term at the surface is used. We obtain the surface Green's function by means of the transfer-matrix method and use the generalized Friedel sum rule to treat charge-transfer effects self-consistently. We find the surface magnetization to be dependent on surface-bulk coupling. We also find that majority states are mostly localized at the surface, while minority states are mainly delocalized. The relevance of our results to experimental data on Ni, Co, and Fe overlayers is discussed.