ONION-LIKE GRAPHITIC PARTICLES

Nanometric graphitic structures (fullerenes, nanotubes, bucky-onions, etc.) form in different harsh environments (electric are, electron irradiation, plasma torch). In particular, the onion-like graphitic particles may display a wide range of structures, going From polyhedral to nearly spherical. High-resolution electron microscopy is the primary tool for studying these systems. On the basis of HREM observations, we discuss the energetics and possible formation mechanism of these multi-shell fullerenes. The better understanding of the underlying processes would allow the development of an efficient production method.