TG, DSC, XRD, and SEM studies of the substituted lithium ferrite formation from milled Sm2O3/Fe2O3/Li2CO3 precursors.

Formation of substituted lithium ferrite Li_0.5Sm_xFe_2.5–xO₄ (where x = 0.06 and 0.2) from Sm₂O₃/Fe₂O₃/Li₂CO₂ precursors was studied by X-ray diffraction analysis, thermogravimetry, differential scanning calorimetry, and scanning electron microscopy. The mixture of powders was subjected to preliminary mechanical activation in a planetary mill. We analyzed samples based on the precursors and synthesized at 900 °C for 4 h in a laboratory furnace. It was found that ball milling of the precursors mixture in a planetary mill increases the powder reactivity. In spite of this, no substituted lithium ferrites were formed. It was shown that a two-phase composite that consists of pure lithium ferrite Li_0.5Fe_2.5O₄ and SmFeO₃ is formed during synthesis. An increase in the Sm₂O₃ content in the initial mixture provides an increase in the amount of the formed SmFeO₃ phase. The synthesis of Li_0.5Fe_2.5O₄ ferrite was confirmed by XRD analysis data, the Curie temperature (627–630 °C) measured using TG analysis in a magnetic field, and by the presence of an endothermic peak on the DSC curve corresponding to the order–disorder transition in the Li_0.5Fe_2.5O₄ phase. [ABSTRACT FROM AUTHOR]