Magnesium diffusion in wurtzite-type GaN crystal

The behaviors of Ga and N vacancies (Schottky defects, Frenkel defects), lattice-site and interstitial Mg atoms, and interstitial H atoms have been studied in the wurtzite-type GaN crystal by molecular dynamic simulation. The diffusivity of interstitial Mg atoms on the (0001) plane is predominant compared with the diffusivity along the [0001] direction. Diffusion coefficients of interstitial Mg atoms are composed of two Arrhenius formula for temperatures from 850 K to 2000 K. The one reflects the high-possibility occurrence of jumping movements among cage centers of hexagonal crystal structure for higher temperature. The other reflects the thermal vibration at the cage center for lower temperature.