Abstract
Extremely thin graphite filaments with a tubular structure were grown in carbon deposits formed on the negative electrode during generation of fullerenes by dc carbon-arc-discharge evaporation. The filaments and small graphite particles coexist in the central portion of the deposits. Three kinds of morphologies of carbon, namely nanotubes, polyhedra and sheets were observed in transmission electron micrographs. The filaments were formed in He, Ar or CH4 gas environment at a pressure between 20-200 Torr.