A study was made of the structure and formation yields of atomic-scale defects produced by low-dose Ar ion irradiation in bundles of single-wall carbon nanotubes. For this purpose, empirical potential molecular dynamics and simulated ion impact events over an energy range of 100 to 1000eV were used. It was shown that the most common defects produced at all energies were vacancies on nanotube walls which, at low temperatures, were metastable but long-lived defects. Also calculated was the spatial distribution of the defects, which proved to be highly non-uniform. It was also shown that ion irradiation gave rise to the formation of inter-tube covalent bonds mediated by carbon recoils and nanotube lattice distortions due to dangling-bond saturation. The number of inter-tube links, as well as the overall damage, grew linearly with the energy of the incident ions.

Ion-Irradiation-Induced Defects in Bundles of Carbon Nanotubes. E.Salonen, A.V.Krasheninnikov, K.Nordlund: Nuclear Instruments and Methods in Physics Research B, 2002, 193[1-4], 603-8