ENERGETICS FOR THE NEW FORMS OF CARBON-CLUSTERS

The growth of closed C(n)-structures like fullerenes, shelled fulleren es, tubules and capped tubules controlled by the interplay of surface- and bending-energy is studied. Tubules are less stable than correspon ding fullereness C(n), and these are for n > n(c) less stable than she lled fullerenes. Growth of fullerenes from graphite sheets requires bo nd breaking and bond rearrangement to form pentagons and finite temper atures to overcome energy barriers. Thermodynamical arguments are used to discuss the temperature- and size-dependence of the formation of t he new forms of carbon. We argue that trapping of foreign atoms or mol ecules inside the closed structure may be achieved most efficiently by mixing these with carbon clusters before caging occurs.