SEGREGATION EFFECT ON SURFACE COMPOSITION IN ALLOY SPUTTERING

The modified dynamic TCIS (Transport and atomic Collision cascade of energetic Ions an Solids) Monte Carlo program including the radiation-enhanced Gibbsian segregation (REGS) is employed to estimate the compositional distributions at surface of the Au_0.56Cu_0.44 alloy under 2keV Ar⁺ ion bombardment at high dose. The calculation results exhibit that the Au composition enriches in the first layer (74 at.%), depletes in the second layer (37 at.%) and gradually rises with depth to the bulk composition. The effect of the relation between sputter depth and segregation layer on the surface concentration of Au_0.56Cu_0.44 is also discussed.