Thermal stability of Fe3Si-based nanocrystals

We studied the thermal stability of nanocrystalline (Fe₃Si)_0.95Nb_0.05 and Fe₃Si alloys prepared by high-energy ball milling. Alloys were characterized by Mössbauer spectrometry, as well as X-ray diffractometry and transmission electron microscopy. The Nb-containing alloy was considerably more stable against grain growth than was the binary Fe₃Si alloy. Mössbauer spectrometry showed that the Nb atoms segregated away from the DO₃ ordered domains, probably to grain boundaries, and thus provided a strong suppression on grain growth.