A study was made of the elementary diffusion jumps of Fe atoms in ordered single crystals with Fe contents of 50.5, 55, 66 or 75at%. This was done by comparing the results of quasi-elastic 57Fe Mössbauer spectroscopy with those obtained by using other methods. It was concluded that the mechanism was independent of the alloy composition. Thus, Fe atoms jumped into second-nearest or third-nearest neighbor sites on their own sub-lattice, via anti-structure sites on the Al sub-lattice. Because the disorder increased with increasing Fe concentration, the residence time of Fe atoms on the anti-structure sites increased at the same time.

R.Feldwisch, B.Sepiol, G.Vogl: Nuovo Cimento D, 1996, 18[2-3], 247-51