Surface composition of clean and oxygen-covered Au3Cu alloy

Abstract

Surface segregation behavior of clean and oxygen-adsorbed Au3Cu systems has been studied theoretically within the tight-binding formalism. It has been found that for the clean Au3Cu system the top layer is Au enriched, while the second layer is Cu enriched. In the presence of a monolayer of oxygen atoms, on the other hand, there is a segregation reversal in the top layer which becomes Cu enriched. The above findings are in total agreement with the very recent experimental impact collision ion-scattering spectroscopic results. © 1993 The American Physical Society.