MOLECULAR DYNAMIC STRUCTURE INVESTIGATIONS OF THE ADSORPTION AND BONDING OF CXHY-HYDROCARBON MOLECULES RADICALS ON A DIAMOND (111) SURFACE

Elementary reaction mechanisms for adsorption and chemical bonding of (CxHy fragments (molecules, radicals, clusters) to a clean, unreconstructed and fully or partly hydrogenated diamond (111) surface are studied by molecular dynamic (MD) structure investigations. Applying the Born-Oppenheimer approximation the forces moving the hydrocarbon species via MD to the bonding formation with the crystalline substrate are calculated within an alternative MD-density functional (DF) approach, which uses localized atomic orbital basis functions. In our first results using the method we obtain the stable and metastable ground state structure configurations of CH, CH2, CH3, C2, C2H, and C2H2 molecules and radical adsorbed on a diamond (111) surface, modelled by a finite cluster. We comment on the dependence of the adsorbed cluster geometries on the surface dangling bond density and we discuss the energetically most favourable configurations in relation to low temperature, low pressure diamond growth conditions.