Atom distributions in sigma phases. I. Fe and Cr atom distributions in a binary sigma phase equilibrated at 1063, 1013 and 923 K

Extensive single-crystal Mo Kct Bragg-diffraction data sets were collected and analyzed from sigma (a) phases with compositions near Cr4sFe52 that had been annealed at three temperatures (1063, 1013 and 923 K) within the region of a-phase metastability. Precisions of measurement varied from <1% for the relatively few intense diffraction maxima to ~10-20% for the more numerous weak reflections. No clear indication of the