Synergistic stabilization of metastable Fe23B6 and <i>γ</i>-Fe in undercooled Fe83B17

Abstract

Previous investigations of undercooled liquid Fe83B17 near the eutectic composition have found that metastable crystalline phases, such as Fe23B6, can be formed and persist down to ambient temperature even for rather modest cooling rates. Using time-resolved high-energy x-ray diffraction on electrostatically levitated samples of Fe83B17, we demonstrate that the Fe23B6 metastable phase and fcc γ-Fe grow coherently from the undercooled Fe83B17 liquid and effectively suppress the formation of the equilibrium Fe2B + bcc α-Fe phases. The stabilization of γ-Fe offers another opportunity for experimental investigations of magnetism in metastable fcc iron.