Atomic structures and energies of partial dislocations in wurtzite GaN

The atomic structures of 1/6<20 (2) over bar3> partial dislocations delineating the I-1 intrinsic basal stacking fault in wurtzite GaN are modelled using an empirical interatomic potential in combination with anisotropic elasticity calculations. Twelve stable configurations are obtained for each polarity, and their core radii, energies, and atomic configurations are given. The 5/7-atom ring core in which the atoms are tetrahedrally coordinated is found energetically favorable among the edge dislocation configurations. For the mixed type partials, 5/7- and 12-atom rings are obtained as low-energy cores, but none of them is found to comprise only tetrahedrally coordinated atoms. Each of them is found energetically favorable under distinct structural conditions.