The isochronal recovery of quenched Al-In alloys

The isochronal recovery of quenched-in electrical resistivity has been investigated in a series of dilute binary alloys consisting of up to about 500 atomic p.p.m. In in Al. The strong, systematic dependence of the individual recovery stages on the In content and on the quenching temperature can be explained by the existence of two stages of association between vacancies and In atoms. The more stable of the bound defects is a pair consisting of one vacancy and one In atom. The existence of less stable, vacancy-rich clusters in alloys for which there are vacancies in excess of the In content at the quenching temperature is strongly implied. These vacancyrich clusters may be triplets consisting of two vacancies associated with one In atom.