Binding energies between a vacancy and an atom of lead or gold were measured with the same method as those previously reported. The solid solubility of lead or gold in aluminium is very small, and the small quantity of precipitates are
found along grain boundaries in this experiment. Therefore, it was not possible to determine the value of binding energy, but the lower limit of binding energy was estimated. The values of lower limit for Pb-Vacancy and Au-Vacancy binding energy were 0.38 eV and 0.35 eV, respectively.