Exact result for bimetallic interfaces

Abstract

Exact analytic expressions for the change of electrostatic potential across either half of a bimetallic junction and across the metallic region of a metal-vacuum surface are derived in terms of bulk properties. The results for the bimetallic interface are compared in detail with numerical calculations based on the density-functional formalism. The result for the metal-vacuum surface coincides with the one obtained by Budd and Vannimenus using a different method.