Nucleation behavior of cage structure of carbon in the presence of charge

The charge is produced in abundance in the processing condition of the cage structure of carbon. Considering low ionization energy and high electron affinity of carbon clusters compared with those of single atom or molecule, the carbon clusters are expected to be charged in such ionizing conditions. The charge is suggested to affect the nucleation behavior of a cage structure of carbon at least in two respects. First, the Coulomb energy term, which is newly introduced by charge, can make the energy well in the curve of the free energy versus number of atoms. In combination with the suitable driving force for precipitation of condensed carbon, the energy well will make stable the carbon clusters containing certain number of atoms with respect to both shrinking and growing, increasing the lifetime of the cluster of constant size. Second, the minimization of Coulomb energy favors the loose structure of carbon while that of the surface energy favors the compact structure. In terms of Coulomb energy, the cage structure is favored over the compact one as the cage structure of soap bubble is favored by the electrical double layer on the water surface. These effects of charge were examined based on the classical Thomson equation. (C) 1999 Elsevier Science B.V. All rights reserved.