Electronic theory for surface segregation: Noble-metal alloys

Abstract

A theory for segregation at the surface of noble-metal alloys is presented. The calculation involves a self-consistent solution of the tight-binding Hartree Hamiltonian within the cluster-Bethe-lattice approximation. The effects of electronic charge transfer on surface segregation are given particular attention. The theory is applied to the study of the systems AuAg, AuCu, and AgCu. Comparisons are made with existing experimental data.