Published online by Cambridge University Press: 15 February 2011
Very hot carbon vapor was deposited on highly-oriented pyrolytic graphite (HOPG) and on sapphire substrates. Using atomic force microscopy, the obtained carbon structures are analyzed. It is found that carbon nanotubes and cones had formed on the graphite substrate but not on sapphire. Instead, spherical-type nanoparticles are analyzed on sapphire. A particle with double-conical shape is found on the graphite substrate. The two observed cone angles 19° and 60° are explained by perfect network closure of sectors of curled graphene sheets.