Atomistic modeling, based upon density functional theory within the framework of the generalized gradient approximation, was used to reveal trends in the energetics and electronic properties of single, double and triple defects in the B2-phase alloy; without phase transformation. A systematic study was made of vacancy, B, C and N replacing Fe or Al atoms in a super-cell structure consisting of 16 atoms. Changes in the structural properties and lattice parameters, due to the addition of defects to the FeAl matrix, were compared. The site preference of each type of defect was deduced from the total energy calculations. The trends in the densities of states and valence charge profiles were considered; together with the bond mechanism (ionicity and covalency).

Energetics and Electronic Properties of Vacancies, Antisites and Atomic Defects (B, C, and N) in B2-FeAl Alloys. A.Kellou, H.I.Feraoun, T.Grosdidier, C.Coddet, H.Aourag: Acta Materialia, 2004, 52[11], 3263-71