A study was made of the structure and formation of atomic-scale defects produced, by low-dose Ar-ion bombardment, in bundles of single-wall C nanotubes. 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. At low temperatures, these were metastable but long-lived defects. Calculations were also made of the spatial distribution of the defects, and this proved to be highly non-uniform. It was also shown that ion bombardment gave rise to the formation of inter-tube covalent bonds, mediated by C

recoils, and to nanotube lattice distortions due to dangling-bond saturation. The number of inter-tube links, as well as the overall damage, increased linearly with the energy of 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 Section B, 2002, 193[1-4], 603-8