Characteristics of Pd deposition on the MgO(111) surface

Abstract

We present a first-principles study of the adsorption of a palladium monolayer on the polar MgO (111) surface. On the clean unreconstructed MgO (111) surface, our spin-polarized calculations confirm the existence of partially occupied states in the gap on both oxygen and magnesium terminations. The adsorption characteristics of Pd are controlled by the strong polar character of the surface and thus differ substantially from those reported for the (100) surface. In particular, strong electron transfers and/or orbital hybridization between the Pd atoms and the substrate take place, inducing important changes of the density of states at the Fermi level and consequently modifying the magnetic properties of the deposit. The adhesion energies are high and the adsorption process stabilizes significantly the polar surface, in agreement with experimental observations on a parent system Cu/MgO(111). The calculated energetic parameters of the interface suggest the possibility of a total wetting of the (111) surface by palladium, at variance with the (100) orientation.