Bombardment-induced segregation of Cu in Pt-Cu alloy observed using different energy Auger line combinations

Pt_0.19Cu_0.81 alloy scraped in situ was bombarded by energetic (0.2–2 keV) argon ions and the surface compositions under steady-state bombardment were determined with different energy Auger line combinations. It is found that the outermost surface is enriched in Cu, but that its concentration rapidly decreases to a minimum at the second layer then increases slowly to the bulk value. This fact strongly suggests the existence of a bombardment-induced Gibbsian segregation even at room temperature.The project was supported by the National Natural Science Foundation of China