Point defects in bulk crystals were investigated by using positron annihilation to identify defect structures which were closely related to anomalous grain growth. It was found that self-interstitial type defects were clearly observed in crystals which had been grown by annealing under a Se atmosphere. This results suggested that interstitial-type defects strongly enhanced atomic migration, due to their instability in the crystal, and assisted recrystallization via dislocation climb during annealing.

K.Terashima, E.Tokizaki, A.Uedono, S.Tanigawa: Japanese Journal of Applied Physics, 1993, 32[I-2], 736-40