In this work, we present a systematic study of the effects of graphitizatio
n on the structural perfection of multiwalled carbon nanotubes. High purity
nanotubes were produced by a low temperature CVD method and subsequently a
nnealed at temperatures between 1600 and 3000 degreesC. The nanotubes were
characterized for chemical purity, interlayer spacing, and defect healing.
The graphitization procedure was found to remove residual metal catalyst in
the nanotubes and reduce the wall defects as reflected in a reduced interl
ayer spacing between the graphene shells. Graphitization presents a low-cos
t, commercially viable method of purifying and ordering multiwall carbon na
notubes. (C) 2001 Elsevier Science Ltd. All rights reserved.