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

Abstract

Formation of substituted lithium ferrite Li0.5SmxFe2.5–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 Li0.5Fe2.5O4 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 Li0.5Fe2.5O4 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 Li0.5Fe2.5O4 phase.