Experiments on diamond growth by chemical vapour deposition indicate that atomic oxygen converts the diamond (100)-(2 x 1) surface to the (1 x 1) structure. Ab initio total energy calculations were performed on a cluster of carbon atoms simulating the (100) surface in order to investigate the effect of oxygen on surface reconstruction. Calculations were reported for the clean surface and for O atoms adsorbed atop carbon and at a C-C bridge site. Bridge and atop carbon sites for oxygen have nearly identical adsorption energies and adsorption of O at either site prevents the C(100)-1 x 1 to 2 x 1 dimerization reconstruction. Adsorption of oxygen at one bridge site affects, but did not prevent, the dimerization of an adjacent pair of surface carbon atoms.

Effects of Oxygen on Surface Reconstruction of Carbon. J.L.Whitten, P.Cremaschi, R.E.Thomas, R.A.Rudder, R.J.Markunas: Applied Surface Science, 1994, 75[1-4], 45-50