Hydrocarbon adsorption on a diamond (100) stepped surface

We present theoretical studies of various hydrocarbon radicals and molecules on the (100) surface of diamond. We use molecular dynamics and a dynamical quenching algorithm to calculate the energetics of different adsorption configurations, allowing for full relaxation of the underlying lattice. We use a parametrized many-body potential function that has been used for energetics calculations with a great deal of success [D. Brenner, Phys. Rev. B 42, 9458 (1990)]. Our calculations show that adsorption of hydrocarbons on either the flat terraces or near different types of step edges give small variations of binding energies and equilibrium configurations. This reflects the strong covalent bonding pervasive in the carbon systems, which forces the strain fields and bonding energetics to be determined to a great extent by the local environments. We analyze the consequences of these results for the dynamics of growth under typical conditions.