On the mechanism of carbon nanotubes synthesis by laser ablation

Qualitative analysis of the gas-dynamical phenomena by the laser ablation of graphite under conditions of single-wall carbon nanotubes (SWNTs) suggests to reconsider the currently assumed mechanisms of SWMT formation in this technique ("scooter" and other vapor-based ones) and to conclude that it is a form of solid-liquid-solid catalytic graphitization of amorphous carbon or other imperfect carbon forms. The proposed mechanism of melting of catalyst particles followed by precipitation of SWNTs allows to explain the observed dependencies of the SWNT yield on the synthesis temperature and pressure. Critical inspection of the literature data shows that it might also play a role in other physical and chemical deposition techniques of SWNT synthesis (cw-laser, solar furnace, arc-discharge, hydrocarbon decomposition, CO-disproportionalization).