Point defects, including vacancies, adatoms and Stone-Wales defects, close to a (5,5) single-walled carbon nanotube open end were studied using density functional theory, semi-empirical PM3 methods and the empirical Brenner potential. It was found that the defect’s stability increased as it became closer to the single-walled carbon nanotube open end. Based upon the results, a model for removing defects from a growing single-walled carbon nanotube was proposed in which the defects diffused to the single-walled carbon nanotube end. The calculations showed that the semi-empirical PM3 method compared well with density-functional theory results, and was accurate enough for studying defect formation in single-walled carbon nanotubes. The empirical Brenner potential led to large errors and was sometimes not even qualitatively correct.

Theoretical Study of the Stability of Defects in Single-Walled Carbon Nanotubes as a Function of Their Distance From the Nanotube End. F.Ding: Physical Review B, 2005, 72[24], 245409