In order to study behaviors of vacancies near edge dislocations, the lifetime and coincidence Doppler broadening of positron annihilation on Ni and Fe deformed at high speed and low speed were measured. The formation and migration energies and positron annihilation lifetime of vacancies associated with edge dislocations were also calculated. In the experiments, the existence of vacancies associated with edge dislocations, previously predicted by calculation, was confirmed. Vacancies were released from the edge dislocations at 573K in isochronal annealing for 10h in Fe. These experimental results were explained by a calculation based upon a rate theory. The effect of vacancy diffusion along edge dislocations was also studied, and the obtained results corresponded to those of previous experiments on vacancy self-diffusion along dislocations using the radioactive tracer method.

Behavior of Vacancies Near Edge Dislocations in Ni and α-Fe - Positron Annihilation Experiments and Rate Theory Calculations. K.Sato, T.Yoshiie, T.Ishizaki, Q.Xu: Physical Review B, 2007, 75[9], 094109 (11pp)