Formalism to model stacking fault effects on surface phase stability in alloys

Abstract

Based on the first-principles calculation, we propose a formalism to model stacking fault effects on configurational energetics at the surface, which can be additional major factors governing surface phase stability in alloys with the example of the close-packed surface of Pt-Re alloys. The Pt-Re alloys exhibit several stable surface structures with stacking sequences different from the bulk for ground as well as random states. Stacking sequences for stable surfaces significantly depend on surface composition, which is mainly due to the marked coupling contribution between stacking and atomic configurations to the total energy. The proposed formalism successfully confirms the importance of stacking fault effects on surface phase stability in alloys.