The positron annihilation technique was used to identify the nature of the vacancy-type defects in the D03 and B2 phases of this system. Seven alloys, with Al concentrations ranging from 22.7 to 48at%, and subjected to various thermal treatments, were examined. Positron lifetime calculations for the expected defects in the 2 phases were also performed in order to facilitate defect identification. In the B2 phase, 2 types of defect were identified. These were a thermal complex formed by a Fe-divacancy and an Al antisite, and a Fe-vacancy. No constitutional vacancies were found in the D03 phase.

A Positron Study of the Defect Structures in the D03 and B2 Phases in the Fe–Al System. N.de Diego, F.Plazaola, J.A.Jiménez, J.Serna, J.del Rı́o: Acta Materialia, 2005, 53[1], 163-72