The atomic structures of a and c dislocation cores in the wurtzite gallium nitride were studied by atomic computer simulation using an interatomic potential of the Stillinger-Weber type. Initially, the field of displacements was imposed according to the classical linear elasticity theory and then the system was relaxed to the minimum energy. The dislocation cores present multiple structures that could be related to the location of the dislocation line. The shape and extension of the dislocation cores were analyzed by means of the atomic relative displacements map. The core energy Ec and core radius rc were determined by fitting the strain energy stored in the cylinder of radius R, centered on the dislocation line, to the expression Es(R) = A0 ln(R/rc) + Ec.

Atomic Structure of Dislocation Cores in GaN. A.Béré, A.Serra: Physical Review B, 2002, 65[20], 205323 (10pp)