The migration of various species (H, CH3, CH2, C2H, C2H2) on the (111) surface was investigated theoretically by using a cluster approach and second-order Møller-Plesset perturbation theory. The order of the energy barriers which were obtained for a single jump, between 2 neighboring radical sites, was: CH2 (52) < H (248) < C2H (350) = CH3 (353kJ/mol). The C2H2 species was assumed to migrate via alternating 1-fold and 2-fold site adsorption to the surface. The corresponding barrier for C2H2 was 186kJ/mol. The present type of surface migration of chemisorbed species was, with 1 exception, expected to be energetically favorable in comparison with any desorption process. In the case of C2H2, a desorption process was expected to be energetically favorable.

Surface Migration during Diamond Growth Studied by Molecular Orbital Calculations. K.Larsson, J.O.Carlsson: Physical Review B, 1999, 59[12], 8315-22