The formation mechanism of chiral carbon nanotubes

Abstract

The nuclei and the formation mechanism of chiral carbon nanotubes, namely, single-, double-, and triple-walled carbon nanotubes are simulated by the first principle density functional theory. The formation mechanism from nuclei to corresponding infinitely long carbon nanotubes occurs spirally and via absorbing carbon atoms layer by layer. Carbon atoms at the open end are metastable state compared with ones in the tube wall or the closed end, which indicate the growth point of chiral carbon nanotubes is located at the open end. Growth of outer layer tubular clusters takes precedence over the inner layer in the process of forming multi-walled nuclear structures. Because of the ratio of carbon atoms at the open end to all carbon atoms decreases, the stability of the tubular clusters increases with their length. The infinitely long carbon nanotubes are obtained by executing periodic boundary conditions depend on corresponding nuclear structures.