A New Method for Synthesis of FeMnO3 Ceramics and its Phase Transformation

Abstract

FeMnO3 powders were synthesized through a modified polyacrylamide gel route. The gel and the heat treated final powders have been characterized by X-ray diffractometry (XRD), differential scanning calorimetry and thermogravimetric analysis (TG/DSC) and field-emission scanning electron microscopy (SEM). Phase transformation sequence of dry gel during heating is (Mn+3,Fe+3)2O3→(α-Mn2O3)·(α-Fe2O3)→FeMnO3. The thermal expansion properties of as-prepared sample were determined. From 100 to 700 °C, the average coefficient of expansion is 9.0139×10-6 /K. The experimental results demonstrates that the FeMnO3 sample exhibit a ferromagnetic transitions with TN ≈ 40 K.