AB-INITIO STUDY OF THE SURFACE AND INTERFACIAL PROPERTIES OF A LAYERED MGO NIO FILM/

The equilibrium surface geometries of MgO rind NiO, and the surface/in terface geometry of layered composite thin films of these two oxides, are computed from first-principles periodic calculations within the un restricted Hartree-Fock approximation. Calculated binding-energy shift s of the Ni 2p core levels caused by geometric perturbations in the la yered films are of the correct order of magnitude to account for publi shed x-ray photoelectron spectroscopy results. Recent spectroscopic da ta may thus be interpreted in terms of an ioniclike model with modest surface relaxation.