The diffusion process of the vacancy near diamond (001) surface and the effects of temperature on the vacancy diffusion were investigated by molecular dynamics simulation. The results showed that when the temperature was about 1000K, the vacancy in the second layer begins to diffuse to the surface. In the 1400-2000K temperature range, the vacancy could migrate to the surface. This result was in a good agreement with that of experiment and other calculation. In the temperature range of 1400 to 1800K, two migration stages were observed in the vacancy diffusion process, which correspond to two maxima in the mean square displacement curves. In addition, the vacancy diffusion path was obtained without any constraints exposed on the atoms and the calculated diffusion barrier of the vacancy near the diamond (001) surface was about 0.42eV. The effects of vacancy number and various vacancy arrangements on vacancy diffusion at a given temperature were also considered.

The Vacancy Diffusion near Diamond (001) Surface by Molecular Dynamics Simulation. Hu, X.J., Dai, Y.B., He, X.C., Shen, H.S., Li, R.B.: Acta Physica Sinica, 2002, 51[6], 1392