Tight-binding study of the electronic structure of Pd and Pt overlayers on W (011). The role of s electrons

Abstract

The electronic structures of Pd and Pt epitaxial monolayers on a W (011) surface are studied within a self-consistent tight-binding scheme. The effective Pd (Pt) d-band filling found experimentally as well as in theoretical studies for similar systems is reproduced without the necessity of introducing any essential charge transfer. The phenomenon is related to the low-density tail in the local density of states at the Fermi level. The latter effect cannot be described satisfactorily without the inclusion of s electrons into the model. For the Nb and Ta substrates similar conclusions are reached. The attempt to predict the core-level shifts from the corresponding d-electron potential changes yields results that vary from good to unsatisfactory.