The local electronic densities of states at the surface of disordered alloys

Abstract

The local densities of states at a clean as well as at an adsorbate-covered surface of a disordered alloy is studied within the tight-binding approximation using the first terms in a continued fraction series for the electronic Green's function. The dependence of the adatom local densities of states on the alloy composition, adatom position, special local atomic environment around the adatom and the hopping integral between the adatom and its nearest surface atoms is given. Also the binding energy of an adatom is calculated as a function of the alloy composition. We discuss the significance of electron charge transfer for chemisorption and in general for the determination of the electronic density of states at the surface.