Molecular dynamics simulation of dislocations in wurtzlte-type GaN crystal

The microscopic dislocation structures in wurtzite-type GaN crystals were examined by performing a series of molecular dynamics (MD) simulations. The potential was a two-body interatomic one composed of the long-range Coulomb interaction, the Gilbert-type short-range repulsion, the covalent bonding and covalent repulsion of the modified Morse type and the van der Waals interaction. A dislocation was generated by the coalescence of the facing planes of a semi-infinite trench structure in the crystal. The core structure with an eightfold ring was confirmed for edge dislocations along the C direction, though there were a few atoms which were shifted from the core ring structure.