The energetics of Ti atoms in the metallization of diamond films were studied by performing calculations based upon density functional theory, and a composite basis set. Cluster models which consisted of more than 10 C atoms were chosen to simulate the diamond phase with their boundaries saturated with H atoms. When Ti atoms diffused

interstitially from the surface, and into the bulk, the energy barriers were found to be about 40eV. The Ti was found to favor substitutional sites rather than interstitial sites in diamond crystal. The results indicated that the high concentration of Ti in chemical vapor deposited diamond films after metallization would occupy the grain boundaries, rather than the bulk of the diamond grain.

Energetics of Ti Atom Diffusion into Diamond Film. J.Wan, R.Q.Zhang, H.F.Cheung: Computational Materials Science, 2002, 23[1-4], 73-9