Mechanical alloying studies in the Γ(Fe₃Zn₁₀) and Γ₁(Fe₅Zn₂₁) single and mixed phase compositions

Homogeneous or uniform crystalline materials are obtained following the ball milling of pure elemental powders of Fe and Zn in proportions to yield single phases Γ(Fe₃Zn₁₀), Γ₁(Fe₅Zn₂₁), and Γ + Γ₁ mixed phase (Fe₂₅Zn₇₅). Differential scanning calorimetry (DSC) measurements of the as-milled materials show characteristic stages in the temperature range of 50–600 °C prior to establishing stable equilibrium. The activation energies determined from kinetic analyses range from 49 to 189 kJ/mole in these materials. A characteristic stage at 130 °C marking the distinct evolution of the Γ and Γ₁ phases from the intermediate or mixed phase composition is identified from XRD measurements. The identification of a unique Fe site with a quadrupole splitting (QS) of 1.5 mm/s in corroboration with x-ray diffraction (XRD) shows that this stage marks the onset of an in situ transformation prior to the distinct evolution of the homogeneous phases. The Mössbauer effect measurement of the as-milled materials are resolved in terms of four unique Fe sites with QS of 1.1, 0.241, 0.073, and 0.0772 mm/s.