Monocrystalline samples were subjected to uniaxial tensile strains in such a way that dislocations were essentially the only type of defect that was produced. A method was presented which could be used to study the positron trapping mechanism in dislocations, and to investigate changes in the dislocation network as a function of deformation. Numerical data were provided for Al with regard to positron lifetimes, binding energies at a dislocation, and variations in the dislocation density as a function of tensile stress and strain. It was concluded that the model was basically valid, and could be used to make a consistent analysis of positron annihilation in the presence of dislocations; even when the presence of vacancies and grain boundaries complicated the observations. It was suggested that an extended data analysis which covered higher and lower temperatures could treat the de-trapping of positrons from dislocation lines.

K.Petersen, I.A.Repin, G.Trumpy: Journal of Physics - Condensed Matter, 1996, 8[16], 2815-22