Atomic ordering transition in FeCo

Atomic ordering in equiatomic iron-cobalt was investigated using Mössbauer spectroscopy of quenched samples. The order-disorder transition at 730 °C and the "550 °C anomaly" were observed. A statistical phenomenological model was used to determine the temperature dependence of the short-range order parameter; the critical index $\beta$ was found to be 0.324 ± 0.016.