The precipitation behaviors of Cu and Fe in dislocated float-zone crystals were investigated by using transmission electron microscopic and electron beam-induced current techniques. It was found that Cu precipitation on dislocations was significantly affected by the cooling rate of the specimen after contamination. The Cu established precipitate colonies at certain sites on dislocations, but did not decorate other parts, when the specimen was slowly cooled. The preferential precipitation sites were suggested to be non-dissociated edge-type dislocation segments. Rapid cooling of a specimen led to Cu precipitation on all of the dislocations. The Fe uniformly decorated all of the dislocations, regardless of the cooling rate.

B.Shen, T.Sekiguchi, R.Zhang, Y.Shi, H.Shi, K.Yang, Y.Zheng, K.Sumino: Japanese Journal of Applied Physics, 1996, 35[1-6A], 3301-5