The temperature dependence of peak counting rates of gamma - gamma angular correlation curves of positron annihilation was measured for pure Cu, Cu-3.9at%Si, Cu-7.8at%Si, Cu-4.6at%Ga, Cu-8.3at%Ga, Cu-15.0Ga and Cu-8.0at%Mn. All the measurements were performed at thermal equilibrium from temperatures above the melting points to room temperature. Measured data were analyzed according to the positron trapping model and the values of the apparent formation energy of a single vacancy were found to be 1.21, 1.13, 0.92, 1.10, 1.02, 0.88 and 1.19eV, respectively.

The Formation Energies of a Vacancy in Pure Cu, Cu-Si, Cu-Ga and Cu- Gamma Mn Solid Solutions by Positron Annihilation. H.Fukushima, M.Doyama: Journal of Physics F, 1976, 6[5], 677-85