Interpretation of Self‐Diffusion and Vacancy Properties in Copper

Abstract

Abstract Recent tracer measurements of the self‐diffusion coefficient by Rothman and Peterson are analysed in conjunction with the determination of equilibrium concentrations of vacant lattice sites by Simmons and Balluffi and the isotope effect on self‐diffusion. The following values for monovacancy and divacancy properties are obtained (in the usual notation): E = 1.03 eV, E = 1.06 eV, S ≈ 0.3 k , E − E 0.54 eV, divacancy association entropy Δ S 2 V ≈ 2 k , temperature coefficient of monovacancy self‐diffusion energy 2 α = d ( E + E )/d( kT ) ≈ 0.5, frequency factors for mono‐ and divacancy migration v exp ( S ) = 1.4 × 10 14 s −1 , v exp ( S / k ) = 1.6 × 10 14 s −1 . The monovacancy jump frequencies near room temperature are in excellent agreement with the values obtained from dislocation pinning experiments of Thompson and Paré.