On the nature of frenkel defects in concentrated AuAg alloys

The behaviour of interstitials in concentrated AuAg alloys (1 to 50 at% Ag) is investigated by isochronal annealing of the residual resistivity after 3 MeV electron irradiation below 8.5 K and by damage rate measurements up to 135 K. The resistivity changes are evaluated as a sum of a contribution due to defects and a contribution caused by short range order formation. It can be concluded that close pair recombination takes place in only one single broad stage I. Above this stage I a free migration of interstitials occurs with very short path lengths due to a strong trapping by configuration traps. Therefore the ordering effects are small and can be clearly detected only in Au-50 at% Ag. The annealing curves reveal strong ordering effects caused by a migration of vacancies for temperatures above 240 K. The results are in agreement with those of high-temperature irradiation experiments and of quenching experiments. They are in complete accordance with the one-interstitial model.