The atomic-scale diffusion mechanism of B in diamond was investigated by molecular dynamics simulation. A substitutional B atom diffused to the self-interstitial site when there exists a self-interstitial C atom in its nearest tetrahedral center and the system temperature was high. More important, the bond between B and the self-interstitial C atom was never broken during the diffusion process, indicating that Bs–Ci pairs diffused in the lattice by the interstitial mechanism. The results suggested that B diffusion was mediated by C self-interstitial and not by the vacancy mechanism. In addition, the estimated activation energy and the diffusion exponential prefactor of B diffusion in diamond were found to be 0.23eV and 1.123 x 10−6cm2/s, respectively.

Molecular Dynamics Simulation of Boron Diffusion in Diamond. X.J.Hu, Y.B.Dai, H.S.Shen, X.C.He: Solid State Communications, 2004, 132[8], 557-60