Atomistic analysis of surface segregation in Ni–Pd alloys

Atomistic analysis and large-scale atomistic simulations using the Bozzolo–Ferrante–Smith (BFS) method for alloys were performed to investigate surface segregation in Ni–Pd alloys as a function of temperature, crystal face, and composition. Pd-enrichment of the first layer was observed in (1 1 1) and (1 0 0) surfaces, and enrichment of the top two layers occurred for (1 1 0) surfaces. In all cases, the segregation profile shows alternating planes enriched and depleted in Pd in a decreasing oscillatory profile. Based on atom-by-atom static energy calculations, an explanation for the observed surface features is presented in terms of competing chemical and strain energy effects.