Vacancy Trapping in Fcc Metals Studied by Perturbed Angular Correlations

Abstract

Already in the early sixties, Hinman et al. ¹⁾have studied elementary point defects — their production, migration, agglomeration and trapping — by perturbed angular correlation (PAC) measurements on ¹¹¹In recoilimplanted in silver. About 10 years later, the same system was investigated by Behar and Steffen who ²⁾were the first to discover a radiation induced unique quadrupole frequency. Since then, there has been a steady stream of over 30 publications on defects in fcc metals. Till now, PAC measurements using ¹¹¹In as a probe have revealed altogether 17 discrete frequencies in 7 fcc metals (Ag ¹⁻⁴⁾, Al ⁵⁻⁶⁾, Au ⁷⁾, Cu ⁸⁻⁹⁾, Ni ¹⁻¹²⁾, Pd ¹³⁻¹⁶⁾, Pt ¹⁶⁻¹⁸⁾), each frequency standing for a different but well defined lattice defect. It is the aim of this paper to classify these defects by comparing results obtained for various metals, rather than to discuss each metal separately. The restriction to fcc metals and to ¹¹¹In is not as severe as it might seem, because these systems constitute the only body of data that allows systematic comparisons.