Some properties of Cu-Au alloy surfaces

The purpose of this article is to review some recent studies of the electronic structure in the vicinity of the low-index surfaces of Cu-Au ordered alloys. The work described in this article involved a combination of first-principles calculations, using the self-consistent-field linear muffin-tin orbital method within the atomic sphere approximation (SCF-LMTO-ASA) and a supercell geometry in which the vacuum space above the surface is treated as "empty" spheres, and angle-resolved photoemission measurements. A range of surface-related phenomena were investigated; however the author limits this article to studies of the (100) surfaces of Cu and Cu3Au and the (100) and (001) surfaces of equiatomic CuAuI, The focus is particularly on the occurrence and properties of surface states and surface core level shifts and their dependence on termination. The author shows that photoemission measurements provide a very sensitive probe of such subtle behavior.