MD study on high-energy reactive carbon and oxygen cluster impact leading to surface erosion on diamond

Molecular dynamics (MD) simulations of single Arn, (CO2)n, (C3)n and (O2)n cluster impacts (n ≃ 960) on a diamond (1 1 1) surface are performed in order to investigate the surface erosion process. Unlike the other three impacts which result in a remarkable emission only at higher cluster acceleration energies at Ea ⩾ 75 keV, the O2 cluster impact induces a significant effect from a lower acceleration energy Ea of 30 keV on, and the erosion rate increases almost linearly with the increase of the acceleration energy. These differences are ascribed to the reactive emission pattern via the production of CO and CO2 molecules. The erosion rate per molecule seems to be expressed as a linear function of the impact velocity minus a threshold velocity independent of the cluster size for the O2 cluster impacts.