Diffuse–scattering study of vacancies in quenched gold

Abstract Vacancies in high–purity gold Single crystals have been investigated after quenching from temperatures between 900 and 960°C and after Several steps of an isochronal annealing programme by measurements of the diffuse X–ray scattering intensity close to Bragg reflections, of the lattice parameter change and of the electrical resistivity. From the combined results the volume relaxation of a vacancy was determined to be ΔVrel = − 0·15±0·06 atomic volumes at 5 K. The difference from published values for ΔVrel at high temperatures, that are between — 0·35 and —0·5 atomio volumes suggests a temperature dependence for Vrel in Au. Vacancy clustering is observed at annealing temperatures as low as 0°C, and cluster growth continues right through annealing stage III. The amount of vacancies that agglomerate in clusters (stacking–fault tetrahedra) and the observed decrease in the resistivity per vacancy in the large agglomerates are in reasonable agreement with published results from electron microscope studies.