Molecular Dynamics in Formation Process of Single-Walled Carbon Nanotubes.

Abstract

The formation mechanism of single-walled carbon nanotubes (SWNTs) was studied with the molecular dynamics simulation. Starting from randomly distributed carbon and nickel atoms, random cage structures of carbon atoms with a few nickel atoms were obtained after 6 ns simulation. Nickel atoms on the random cage prohibited the complete closure and anneal of the cage structure into the fullerene structure. In the next stage the simulation cell size was artificially shrunk for realization of proceeding collisions of precursor clusters within the computational time limit. Collisions of such imperfect random-cage clusters lead to an elongated tubular cage structure, which could be regarded as an imperfect SWNTs. Furthermore, we compared simulation results with the FT-ICR mass spectra of the positive clusters generated by the laser-vaporization supersonic-expansion cluster beam source.