THERMAL SHRINKAGE OF DISLOCATION LOOPS AND THE MECHANISM OF SELF-DIFFUSION IN GERMANIUM.

Observations on perfect vacancy loops in germanium at above 600 degree C have shown that the rate of shrinking of a loop is accelerated as it becomes smaller. This feature can be interpreted in terms of the emission of constituent vacancies from each loop and supports the self-diffusion mechanism which is of vacancy type. While each interstitial type loop shrinks with constant speed down to smaller size which is also consistent with the vacancy mechanism.