Sputtering of amorphous hydrogenated carbon by hyperthermal ions as studied by tight-binding molecular dynamics

Although the mechanisms of the erosion of carbon-based materials by low-energy hydrogen ions have recently been addressed from an atomistic point of view [see e.g. Phys. Rev. B 63 (2001) 195415], it is not clear yet whether the quantum-mechanical effects are important for an adequate description of the erosion. We now study the low-energy erosion mechanisms by tight-binding molecular dynamics, which accounts for the quantum-mechanical nature of the interactions between the impinging particle and surface. We simulate the ion-assisted bond breaking in simple model systems like carbon dimers and also model sputtering from realistic hydrogenated carbon surfaces. Our simulations confirm the empirical potential results on the low-energy erosion mechanism, and help one to distinguish between the different mechanisms of the surface erosion.