Surface segregation of Pt in γ′-Ni3Al: A first-principles study Original Research Article

We performed first-principles slab calculations based on the density functional theory to investigate the surface segregation behavior of Pt on the clean (1 0 0), (1 1 0) and (1 1 1) surfaces of γ′-Ni3Al. The results clearly indicate that Pt has a strong tendency to surface segregate in all three low-index surface orientations. Such a conclusion is in complete agreement with a recent experimental finding that Pt segregates to the clean Ni3Al(1 1 1) surface. The tendency of Pt to surface segregate also helps to explain why Pt addition is beneficial to the oxidation resistance of Ni3Al.