Electronic structure of MgO-supported palladium films: Influence of the adsorption site

Although theoretical studies on metal-oxide interfaces were initiated a few decades ago, there is still no consensus on the relative importance of the basic microscopic mechanisms responsible for adhesion. Even in the case of model, nonreactive interfaces (in the absence of strong structural and charge-transfer effects) different theoretical approaches often bring contradictory results on very basic questions, such as, for example, the preferential adsorption site. On the other hand, it is only very recently that conclusive experimental results are available. We present an ab initio full-potential linear muffin-tin orbital study of the electronic structure of a palladium monolayer deposited on the MgO(100) surface. We determine the preferential adsorption geometry and discuss the geometry-dependent characteristics of the electronic structure of the interface. Our analysis concerns principally the layer-projected densities of states, electron redistribution across the interface, and substrate-induced polarization of the deposited metallic layer. We relate the relative stability of alternative adsorption geometries to the details of the interface electronic structure.