Positron annihilation and Mössbauer spectroscopic studies were made of samples with various morphologies which had been obtained by severe deformation and by quenching from high temperatures. Changes in the atomic ordering and defect arrangements after the recovery and annealing of highly deformed and highly disordered samples were studied. It was shown that the predominant component (184ps) in the positron lifetime spectrum of highly disordered samples corresponded to the annihilation of vacancies which preferred to occupy the sub-lattice, of D03 superstructures, which contained both Al and Fe atoms. It was noted that large changes in vacancy concentration occurred only when annealing was performed above the D03  B2 transition at 823K. Heat treatment below this phase transformation resulted mainly in changes in the dislocation density.

Y.Jirásková, O.Schneeweiss, M.Sob, I.Novotný: Acta Materialia, 1997, 45[5], 2147-54