Amorphous-carbon nanotube: The growth intermediates of graphitic carbon nanotube?

Three types of carbon nanotubes, the well-graphitized, unwell-graphitized and non-graphitized, have been observed in the same arc-discharged product by means of transmission electron microscopy. Non-graphitized nanotubes are made of amorphous carbon with plastic-like behavior and are suggested to be the protoform of the well-graphilized nanotube. A four-step model is proposed to account for the presence of three types of nanotubes and for the growth mechanism of the graphitized nanotube. The model can also explain the various experimental observations in the carbon nanotube production