Ion bombardment-induced subsurface composition modifications in alloys at elevated temperatures

Modifications of subsurface alloy composition during high-temperature sputtering were studied using a comprehensive kinetic model that Includes Gibbsian adsorption, preferential sputtering, displacement mixing, radiation-enhanced diffusion, and radiation-induced segregation. Numerical solutions were obtained for a Cu-40 at.% Ni alloy under 5-keV Ar+ ion bombardment as functions of time and temperature. The model predictions are in good qualitative agreement with recent experimental measurements.