The initial sputtering of Cu(1 0 0) by 1 keV O2 projectiles

Molecular dynamics simulations of the sputter erosion of a Cu(1 0 0) crystal by 1 keV O2 projectiles up to a nominal fluence of 1.7 × 1015 O2 molecules cm−2 are reported for both normal and oblique projectile incidence. O–Cu attractive interactions have been described in the simulations using a many-body Gupta potential that was fitted to ab initio structural and energy predictions for O–Cu clusters. The simulations predict that implanted oxygen atoms segregate from octahedral sites in the bulk to hollow sites at the surface, and that the sputter yield of the target is enhanced by a factor of two due to the efficient formation of CunO clusters. The predicted yields of CunO clusters display a non-monotonic abundance distribution, with a maximum at n = 2–3, in contrast to the monotonic, power-law abundance distribution predicted for Cun clusters.