Neutron powder diffraction measurements were carried out  in situ, at temperatures ranging from ambient to about 1000C, on samples which contained 28, 32.5 or 28at%Al, plus 5at%Cr. Transmission electron microscopic and X-ray data were analyzed in order to obtain information on the temperature dependence of the DO3 and B2 long-range order parameters, on the location of Cr atoms and their effect on the ordering energies, and on vacancy formation and migration. The location of the ternary alloying element in the ordered Al-rich material was shown to be consistent with the interatomic bond energies.

Long-Range Order and Vacancy Properties in Al-Rich Fe3Al and Fe3Al(Cr) Alloys S.M.Kim, D.G.Morris: Acta Materialia, 1998, 46[8], 2587-602