Internal structure and stability of carbon nanoclusters: arc discharge preparation versus CO disproportionation

Carbon nanoclusters prepared at high temperature by arc discharge, and at low temperature by CO disproportionation with and without hydrogen present, were compared in their morphology, internal structures, and stability. Electron microscopy shows similar external morphology in the three different sample types, with the internal structures different depending on the preparation conditions. These differences result in different stabilities. Nanotubes of cylindrical structure are stable to annealing at 1000°C in both helium and hydrogen atmosphere. Two-minute electron bombardment disordered tubes slightly. However, filaments of conical fishbon structure deposited in the presence of hydrogen, significantly deform under the same conditions.