Mössbauer study of the thermally induced transformation of the Fe0.91B0.09 rapidly quenched crystalline alloy

Abstract
The transformation of the Fe0.91B0.09 rapidly quenched crystalline alloy from its original metastable state to its equilibrium state has been studied by Mössbauer effect spectroscopy. It was found that the alloy transforms in a single step from a fine dispersion of orthorhombic‐Fe3B‐like complexes embedded in metallic bcc iron to a system consisting of Fe2B precipitates in the α‐Fe matrix. The kinetics and temperature dependence of the process have been measured. It was determined that the relative fraction of Fe2B increases as Ω=1−exp(−kt3/2) with k=k0 exp(−Ea/kBT), indicating a diffusion‐controlled, Arrhenius‐type transformation, where k0=(1.92±0.26)×1014 s3/2 and Ea=(3.56±0.07) eV/atoms. Magnetization versus temperature scans have been simulated and compared to previously measured scans. A simple picture of the transformation process is given.