The loss of interstitial O from solution was shown to obey second-order kinetics provided that dimer dissociation was not significant at the annealing temperature. Changes in the kinetics of the process, upon annealing at temperatures above 450C, were explained by an increasing effect of this dissociation, provided that dimers diffused much more rapidly than did isolated atoms; and were efficiently trapped. The size of the changes indicated that weakly-bound clusters were responsible for the trapping. The formation of 2 separate series of O clusters which contained odd and even numbers of O atoms was expected to be a consequence of clustering via dimer addition. It was suggested that the odd-numbered series should be attributed to thermal donors.

S.A.McQuaid, R.C.Newman, E.Munoz: Materials Science and Engineering B, 1996, 36[1-3], 171-4