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

Abstract

Formation of substituted lithium ferrite Li 0.5 Sm x Fe 2.5-x O 4 (where x = 0.06 and 0.2) from Sm 2 O 3 /Fe 2 O 3 /Li 2 CO 2 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 0.5 Fe 2.5 O 4 and SmFeO 3 is formed during synthesis. An increase in the Sm 2 O 3 content in the initial mixture provides an increase in the amount of the formed SmFeO 3 phase. The synthesis of Li 0.5 Fe 2.5 O 4 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 0.5 Fe 2.5 O 4 phase.