title: Liquid carbon, carbon-glass beads, and the crystallization of carbon nanotubes.
abstract: The formation of carbon nanotubes in a pure carbon arc in a helium atmosphere is found to involve liquid carbon. Electron microscopy shows a viscous liquid-like amorphous carbon layer covering the surfaces of nanotube-containing millimeter-sized columnar structures from which the cathode deposit is composed. Regularly spaced, submicrometer-sized spherical beads of amorphous carbon are often found on the nanotubes at the surfaces of these columns. Apparently, at the anode, liquid-carbon drops form, which acquire a carbon-glass surface due to rapid evaporative cooling. Nanotubes crystallize inside the supercooled, glass-coated liquid-carbon drops. The carbon-glass layer ultimately coats and beads on the nanotubes near the surface.
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA. walt.deheer@physics.gatech.edu
authors.forename: Walt A
authors.initials: WA
authors.lastname: de Heer
authors.forename: Philippe
authors.initials: P
authors.lastname: Poncharal
authors.forename: Claire
authors.initials: C
authors.lastname: Berger
authors.forename: Joseph
authors.initials: J
authors.lastname: Gezo
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Song
authors.forename: Jefferson
authors.initials: J
authors.lastname: Bettini
authors.forename: Daniel
authors.initials: D
authors.lastname: Ugarte