The annihilation of dislocation loops which had previously been introduced by ion bombardment (3 to 5keV Ar+), followed by threshold-energy electron irradiation, was investigated by means of transmission and high-resolution electron microscopy. It was found that, under electron irradiation, dislocation loops in the ion-bombarded samples contracted. On the other hand, the usual thermal annealing caused the loops to grow. The process accelerated as the irradiation temperature was increased to above 200C in a transmission electron microscope. This phenomenon was also observed at 173K. It was found that the loops lay in the {110} and {111} planes, with Burgers vectors of a/2<110> and a/3<111>. The results were explained in terms of an ionization-related below-threshold mechanism for defect formation.

J.J.Loginov: Fizika Tverdogo Tela, 1995, 37[6], 1703-12 (Physics of the Solid State, 1995, 37[6], 926-31)