Effect of Vacancies on Positron Annihilation and Hyperfine Interactions in Fe-Al Alloys - Ab Initio Study
Vacancies occupying different sub-lattices of D03 structure of Fe3Al alloy were investigated by the full potential linearized augmented plane wave method. The calculations basing on the super-cell approach have been performed for the vacancy concentrations of 1.6 and 3 at.%. For both concentrations the sub-lattice preference for vacancy location was determined. The dependence of vacancy formation energy on magnetic state of structure has been found. The positron lifetimes for the annihilation in the bulk (Fe3Al) and in vacancies have been investigated basing on the ab initio results for the electron density. The effect of vacancies on spin magnetic moment and hy-perfine parameters of Fe atoms neighboring the vacancy was examined. The results are discussed and compared with the data available.
Yuriy Verbovytskyy and António Pereira Gonçalves
J. Deniszczyk et al., "Effect of Vacancies on Positron Annihilation and Hyperfine Interactions in Fe-Al Alloys - Ab Initio Study", Solid State Phenomena, Vol. 194, pp. 272-275, 2013