Carbon nanotubes were formed on HOPG when the graphite faces were
exposed to a stainless steel C60 evaporator heated to 4508C. No nanotubes
were found on gold under the same conditions or when a quartz oven was
used as the C60 evaporator. Interesting conical nanostructures were found
in the insoluble residue from the stainless steel oven. We interpret the
nanotube formation to be due to the presence of small carbon fragments
produced by the catalytic decomposition of C 60 in the oven.