A study of stage II and III recovery in neutron irradiated gold and the influence of mercury impurity atoms

Abstract Spectroscopically pure gold has been neutron irradiated at −196°c to a dose of 5 × 1017 n.v.t. and the isochronal annealing of the radiation damage up to +100°c has been studied from changes in the electrical resistance measured in liquid helium. Three principal annealing peaks at approximately −150°c, −90°c and +20°c superposed upon a continuous annealing have been observed; the third peak is considerably larger than the other two. An almost identical annealing spectrum was obtained for a 0.25 atomic per cent mercury–gold alloy which has been prepared by irradiating gold with thermal neutrons at 80°c, the main difference being that the peaks are slightly smaller. If the alloy is annealed at 345°c for one hour before being irradiated at −196°c the annealing spectrum is even more similar to that observed with pure gold. It is suggested that the first two peaks are due to the migration of interstitials from impurity traps and the third to the migration of vacancies; also, because of the small effec...