Self-diffusion of64Cu in copper single crystals Monovacancy and divacancy contributions

Abstract
Self-diffusion of 64Cu in copper single crystals has been measured over the temperature range 737°–1079°C. The curved Arrhenius plot is evaluated together with earlier tracer data according to the least-squares analysis of Morrison (1975), assuming mono-vacancy and divacancy diffusion to be operative. Neglecting possible temperature dependencies of energies and entropies, the diffusion coefficient can be described by the frequency factors D 1V° = 0 ·13+0·08 −0· and D 2V° = 4·6+6 −2·6 cm2 S−1. The respective activation energies are for the monovacancy and divacancy contributions Q 1V = 47·4 ± 0·6 and Q 2V = 57 ± 3 kcal mole−1.