HRTEM of Initial Oxidation of Carbon Nanotube Tips

Abstract High resolution transmission electron microscopy (HRTEM) and diffraction technique, with their high sensitivity to small variations in periodic structure or lattice imperfections within individual crystals, have made it possible to relate nanostructure to physical properties of individual fullerenes(C60, C70, etc.) and carbon nanotubes. Using HRTEM imaging, in tandem with dynamic image simulation, we have examined the etching patterns of carbon nanotubes in terms of tip geometry and bond strains. Our studies indicate that the progression of oxidation is not random, and is fully determined by the tip structure, of which only a finite number of classes exist. Oxidation of carbon nanotubes prefers to start at the positions which are most strained, which is associated with the arrangement of pentagons. Carbon nanotubes were synthesized using the carbon arc method similar to that used for the synthesis of fullerences. The carbon nanotubes are often capped by carbon shells that fit continuously on the ends of the long cylinder