Single atom chemisorption on a bcc metal

Abstract

The effect of chemisorption of a single atom on the (001) surface of a bcc metal is investigated via the Green's function and the phase shift techniques using the LCAO method and the tight-binding approximation. In particular, we obtain the change in the electronic density of states Δ n due to two different binding sites, the on-site and the centered four-fold-site. For each site, the adatom energy level E a is placed both inside and outside the band, and several adatom-substrate interaction strengths σ are considered. By varying these parameters we obtain a qualitative understanding of the effects on Δ n due to either the adsorption of different atoms or a readjustment of E a arising from a flow of charge onto or away from the adsorbed atom. We compare our results to previous studies of chemisorption on the (001) surface of an s-band simple cubic crystal and find that, although some details distinctive of the bcc metal arise, the overall qualitative features are the same.