Matrix effect of bombardment-induced Gibbsian segregation on Cu depletion at a Cu _x Ni_100−x subsurface

Abstract

A dynamic Monte-Carlo program, including an improved BIGS (Bombardment-Induced Gibbsian Segregation) model was employed to study the matrix effect of BIGS and its influence on Cu depletion at the subsurface under 1 keV Ar-ion bombardment of a Cu−Ni alloy. The calculation results show that not only at high fluences (the steady state) but also at low fluences, the Cu subsurface depletion depends on its bulk composition. This is because the atomic jump rateW ₂₁ of Cu from the second layer to the first layer is correlated to Cu bulk composition at any fluence. We also found that the product of the non-segregating species concentration at the first layer with the segregating species concentration at the second layer plays a more important role than other parameters in determiningW ₂₁ under low current conditions.