Collision dynamics of energetic carbon ions impinging on single-walled carbon nanotubes

By employing atomistic simulations based on an empirical potential, we study the collision dynamics of low-energy carbon ions impinging on single-walled carbon nanotubes. We investigate the energy transferred from the incident carbon ions to the target atoms in the nanotubes. We find that the lowest incident energy needed for the primary knock-on atom to be permanently displaced from its original location is 18 eV, and for the secondary knock-on atom to escape out of the nanotube is estimated to be 28 eV. Moreover, we find that the incident threshold energy strongly depends on the diameter of the nanotube and its chirality, and saturates towards the corresponding value in graphene as the tube diameter increases. Furthermore, a single vacancy and an adatom defects are obtained after optimization using the ab-initio calculations.