The lifetimes of positrons in an edge dislocation, in a jog, and in vacancies which were associated with the dislocation, were calculated for the body-centered cubic phase. The structures of the defects were obtained by means of static relaxation, using the Finnis-Sinclair potential. The positron lifetimes were calculated by using the superposed-atom method. It was found that the positrons were not localized strongly in the pure edge dislocation or the jog. The lifetimes in these were almost the same, and were only a few ps longer than that in the matrix. The vacancy was trapped on the edge dislocation line, and was not entirely collapsed by the strain in the core region of the dislocation. The positron lifetime in the associated vacancy was shorter than that in a matrix vacancy. The results indicated that a deeper trap which was associated with the dislocation line was not the jog but the vacancy.

Y.Kamimura, T.Tsutsumi, E.Kuramoto: Physical Review B, 1995, 52[2], 879-85