Positron annihilation techniques were used to investigate 2 defects which occurred naturally in semi-insulating material. One of them was the AsGa (EL2) defect and the other was the VAs defect. It was found that the distributions of these important point defects were controlled by dislocations.

M.R.Brozel, C.Corbel: Journal de Physique IV, 1995, 5[C1], 63-72