Identification and dynamic characteristics of the defects responsible for the radiation enhancement of atomic mobility in concentrated<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>α</mml:mi></mml:math>-AgZn alloys

Abstract

Strain-relaxation measurements were conducted in order to follow directly under flux the enhanced rate of the stress-induced ordering which occurs in a Ag-30-at.%-Zn alloy, as a result of electron irradiation. From the consideration of activation energies for the quasistationary and stationary states, the migration energies for the two types of elementary defects involved in the observed enhancements were measured to be 0.56\ifmmode\pm\else\textpm\fi{}0.02 and 0.94\ifmmode\pm\else\textpm\fi{}0.02 eV, respectively, for the faster- and the slower-moving species. Further, direct comparison, for specimens in the well-annealed or prequenched condition, of the buildup profiles until a stationary regime is reached, together with quench studies, enabled the unambiguous identification of the faster-moving defect in the irradiated alloy as the single vacancy.