Temperature dependence of the rate of positron trapping by vacancies in gold

Positron lifetimes were measured in high-purity gold in order to study the temperature dependence of the monovacancy-positron specific trapping rate, defined as the positron trapping rate per unit monovacancy concentration. In all cases a positive temperature dependence was found. Equilibrium experiments alone yielded a temperature dependence of T^0.5±0.2 over the temperature range 673-1033 K. Experiments which combined quenching and equilibrium measurements indicated a temperature dependence of T^0.9±0.1 between 243 and 1033 K. Additional measurements at lower temperatures indicated that a positive temperature dependence continues down to 115 K.