Gas-dynamic consideration of the laser evaporation synthesis of single-wall carbon nanotubes

The abundance of carbon single-wall nanotubes (SWNTs) in soot synthesized by pulsed laser evaporation of graphite is studied over a wide range of synthesis conditions. The derived SWNT growth time-scale appears to be much longer than any characteristic time-scale in a simplified model of the relaxation of a high-pressure hot condensing gas bubble in a background atmosphere. It is concluded that SWNT nucleation and growth take place in relaxed, condensed, thermalized evaporation products at an optimal temperature between 850-1250 °C at a rate of few 7m length per second, which is consistent with a condensed state "precipitation" mechanism for the SWNT formation.