Molecular dynamics simulations of healing of a hole in a carbon nanotube under electron irradiation

Molecular dynamics simulations are performed to study healing of a hole in a carbon nanotube under electron irradiation in HRTEM at room temperature. The calculations are carried out using the CompuTEM algorithm as implemented in the MD-kMC code. Hole healing occurs in all the simulation runs. An amorphous patch is formed in the absence of external carbon adatoms only via saturation of dangling bonds. The patch consists of non-hexagonal rings, mostly of 5-, 6- and 7-membered rings, and its formation is accompanied by CNT buckling and narrowing. The amorphous patch growth is observed under further irradiation. Two-coordinated atoms play a leading role in this process.