Transmission electron energy-loss spectroscopy study of carbon nanotubes upon high temperature treatment

Two batches of carbon nanotube materials, grown with a pulsed-laser deposit ion technique but purified and heat treated under different conditions, are investigated with a combination of high- resolution transmission electron microscopy techniques, including electron nanodiffraction and low-loss and carbon K-edge electron energy-loss spectroscopy. These techniques were used to achieve a detailed profile of each material. Heat treating one batch at 1100 degreesC is shown to increase the sp(2)/sp(3) hybridization ratio, wh ile a 2150 degreesC treatment of the other batch fundamentally restructured the material from single walled to a mixture of amorphous and multiwalled material. (C) 2001 American Institute of Physics.