A theoretical model of DC-glow discharge promoted diamond nucleation is suggested based on a semiempirical quantum chemical study of carbon clusters consisting of a few atoms. Under the standard thermodynamic conditions, the formation of planar aromatic is polyaromatic structures is energetically favorable. The influence of the DC-glow discharge is modeled through a shift in the substrate surface potential which, in turn, determines a shift in the valence state ionization potential (VSIP) of atoms adsorbed on the surface. When changes in VSIP exceed 4 eV, the π-interaction of 2p-orbitals of carbon is suppressed. This effect causes the stabilization of tetrahedral, twined and icosahedral structures over the aromatic ones for small carbon clusters. This effect becomes more pronounced as the cluster size increases. These structures are consider to be precursor for diamond growth under chemical vapor deposition (CVD) conditions.
|Number of pages||6|
|Journal||Journal of Crystal Growth|
|Issue number||pt 2|
|State||Published - Mar 1999|
|Event||Proceedings of the 1998 10th International Conference on Vapor Growth and Epitaxy and Specialist Workshops on Crystal Growth, ICVGE-10 - Jerusalem, Isr|
Duration: 26 Jul 1998 → 31 Jul 1998