Quenching-in and annealing-out of point defects in degassed gold held in clean and dirty atmospheres

Abstract

The annealing kinetics of quenched-in vacancies in 99•999% Au for quenches from 700°C and 800°C were studied in pure helium atmospheres and in 80% helium, 20% oxygen atmosphere. It was found that divacancies played the major role in quenches in a pure atmosphere, whereas under the same quench and anneal conditions, but with oxygen present, single vacancies were observed with a shift in E _M from 0•62 ev to 0•80 ev upon addition of the oxygen. A mechanism to explain this behaviour is introduced and past work is interpreted in light of the present findings and the proposed mechanism. An estimate of the minimum solubility of oxygen in gold at 800°C is given as 5 × 10⁻⁵ atomic fraction.