Impurity-interstitial interaction in electron-irradiated aluminium

Abstract

The interaction of migrating Al interstitials with impurities has been investigated by damage-rate measurements in dilute Al alloys with Ag, Ge, Mg, and Zn interstitials at irradiation temperatures between 53 and 178K. For comparison the stage II resistivity recovery has been measured during isochronal annealing in the same material. By applying the diffusion theory of the three-dimensionally migrating interstitial to the data the capture radii of impurities for migrating interstitials have been determined. The effective capture radii of all impurities decrease with increasing irradiation temperature. The impurity Mg loses its trapping capability between 100 and 180K whereas the other impurities do trap interstitials even at 178K. The absolute values of the capture radii are considerably larger than expected from elasticity theory.