In order to observe an anomalously large number of thermal vacancies retained in B2-type FeAl, the alloy was rapidly solidified into ribbons by using a conventional melt-spinning technique, and the density and vacancy concentration of the ribbons were determined by using an Archimedes water immersion technique and X-ray diffraction methods. The lattice constant of as-spun ribbon, which already had a B2-type ordered structure regardless of rapid solidification by melt-spinning, was 2.8992 x 10-10m. This was smaller than that of previously reported water-quenched FeAl alloys; thus indicating lattice relaxation due to the existence of numerous thermal vacancies. The total vacancy concentration of as-spun ribbons was estimated to be approximately 1.38%. This was several hundred times higher than that of pure metals and disordered alloys near to the melting point.

Determination of Density and Vacancy Concentration in Rapidly Solidified FeAl Ribbons. T.Haraguchi, K.Yoshimi, H.Kato, S.Hanada, A.Inoue: Intermetallics, 2003, 11[7], 707-11