In order to investigate interstitial-type dislocation loops, as vacancy sources after a temperature rise in almost perfect crystals, single-scan X-ray Lang topographs were obtained while the specimen was cooled to room temperature, from 295C, at a cooling rate of 1000C/h in air. The interstitial loops were found to be frozen into the crystal, with no multiplication of glide dislocations. Few loops disappeared during cooling.

K.Mizuno, K.Ono, K.Ito, T.Kino: Journal of the Physical Society of Japan, 1995, 64[3], 699-701