On the recovery stages in fcc materials

Abstract

It is shown that the migration activation energy of vacancies in copper resulting from experiments performed in thermal equilibrium is E M IV = 1.06 eV. The same value was also obtained for recovery stage IV after quenching from high temperatures or after irradiation with high energy particles forty years ago. The activation energy obtained for the recovery stage III is the migration activation energy of interstitials E M II = 0.71 eV. Radiation-enhanced 63Ni-diffusion in copper is above the stage III temperature region determined only by interstitials and below the stage III temperature region determined only by dynamic crowdions. Dynamic crowdions jump in pure materials about N = 40 000 times during their life time. In recovery stages I and II correlated interstitial—vacancy pairs annihilate. The activation energy for the annihilation of these pairs increases with increasing distance between correlated interstitials and vacancies. Correlated crowdion—vacancy pairs and crowdions annihilate in the recovery stages I D and I E, respectively, in materials in which crowdions are stable.