Positron annihilation studies of the production of vacancies in copper

Abstract
The Doppler-broadening of the positron annihilation line in copper has been studied with a Ge(Li) detector as a function of temperature. The proportion of annihilations occurring with free electrons has beem measured by analysing the shapes. Various hypotheses have been assessed by parameter optimization. The best value of the vacancy formation energy is estimated to be 1.26+or-0.07 eV.