Structural and magnetic properties of α-Fe2O3 with lithium ferrite prepared using co-precipitation method and annealed at different temperatures

Abstract

Using Co-precipitation method, an attempt was made to prepare lithium ferrite. However, during the synthesis, formation of an additional α-Fe₂O₃ phase along with Li_0.5Fe_2.5O₄ was observed. To reduce the α-Fe₂O₃ phase, samples were annealed at 700°C, 800°C and 900°C temperatures for 2 hours. The investigated samples were then characterized using X-Ray diffraction for phase formation and Rietveld analysis was carried out to determine the different structural parameters such as phase percentage, lattice parameter and cell volume. The Chi square values were observed to be within the limit along with goodness of fit less than 3 for all the samples annealed at different temperatures. Surface morphology was carried out using scanning electron microscope and the average grain size was found to be 1.43 µm for the sample annealed at 900°C. Magnetic properties of samples were investigated, and it was observed that all the samples exhibit low values of saturation magnetization along with coercivity. The presence of two phases such as α-Fe₂O₃ phase and lithium ferrite phase dilutes the exchange interaction, tuning the magnetic parameters.