The atomic-scale diffusion mechanism of boron in diamond was investigated by molecular dynamics simulation. A substitutional boron atom diffuses to the self-interstitial site when there existed a self-interstitial carbon atom in its nearest tetrahedral center and the system temperature was high. More important, the bond between boron and the self-interstitial carbon atom was never broken during the diffusion process, indicating that Bs-Ci pairs diffuse in the lattice by the interstitial mechanism. The results suggested that boron diffusion was mediated by carbon self-interstitial, and not by the vacancy mechanism, and could be described by:

D (cm2/s) = 1.123 x 10-6exp[-0.23(eV)/kT]

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