The diffusion of vacancies near a diamond (001) surface

The diffusion process of the vacancy near diamond (001) surface at different temperatures was investigated by molecular dynamics simulation. The vacancy in the second layer begins to diffuse towards the surface at about 1000 K, and it can migrate to the surface in the temperature range of 1400–2000 K. In the 1400–1800 K temperature range, two migration stages, which correspond to two maxima in the mean square displacement curves, are observed in the vacancy diffusion process. In addition, the vacancy diffusion path is obtained without any constraints imposed on the atoms, and the calculated diffusion barrier of the vacancy near diamond (001) surface is about 0.42 eV.