Annealing of Quenched Defects in Gold

The slope-change method for determination of activation energies of migrating defects is examined using computer-generated data based on a simplified model of the annealing of quenched gold. It is shown that there are two well-defined activation energies. One is the instantaneous activation energy which is characteristic of the defect-annihilating step. The second is the apparent activation energy which is characteristic of the rate-limiting annealing step. The two activation energies can be obtained only if accurate time derivatives of the defect concentration are examined. These ideas are applied to the annealing of high-purity gold quenched from 975^∘{}C. The resistance-annealing curves and their first and second derivatives are studied using a new measuring technique which yields continuous plots of the resistance. The annealing curves are consistent with a simple model involving single vacancies, divancies, and a time-dependent sink concentration. The instantaneous activation energy is 0.52 ±{} 0.03 eV and is identified with the divacancy-motion energy. The apparent activation energy is between 0.70 and 0.95 eV.