Structural reorganization of carbon nanoparticles into single-wall nanotubes

The structural reorganization of carbon nanoparticles into single-wall nanotubes via high temperature annealing in absence of metal catalysts, was monitored by photoemission and x-ray absorption spectroscopy. It has been found that for this system an advanced graphitization process is made possible by the peculiar nanoparticle internal structure containing extended ${\mathrm{sp}}^2$ coordinated domains with a sizable degree of ordering. Possible mechanisms for the formation of nanotubes via self-assembling of carbon aggregates are discussed.