The structure and stability of atomic-scale irradiation-induced defects on the walls of carbon nanotubes were studied using scanning-tunneling microscopy. Scanning tunneling microscopic images of irradiated nanotubes containing the defects were simulated using the tight-binding Green’s function technique. The results showed that, at low temperatures, the defects were stable at macroscopically long time-scales and appeared as hillock-like features in scanning tunneling microscopic images due to growth in the local electron density of states on atoms surrounding the defects.

Stability of Irradiation-Induced Point Defects on Walls of Carbon Nanotubes. A.V.Krasheninnikov, K.Nordlund: Journal of Vacuum Science and Technology B, 2002, 20[2], 728-33