Vacancy migration energy in quenched Al-Mg0.01 alloy by positron annihilation

The isothermal recovery rates of vacancy-impurity complexes in an aluminium-1% magnesium alloy are measured in situ at eight temperatures from variations of colinear annihilation -rays versus time. These data analysed in terms of a time dependant ⁺-trapping model yield two apparent migration energies of 0.8 eV±0.1 eV and 0.9 eV±0.05 eV. The nature of the complexes is discussed and their binding energy is estimated.