Kinetic analysis of lithium–titanium ferrite formation from mechanically milled reagents

In this study, the AGO-2S planetary ball mill was used for mechanical milling of the initial reagents. The X-ray diffraction patterns for mechanically activated mixtures show increased of the width intensities of reflections due to decreased crystallite size which caused by mechanical grinding. Thermal analysis showed that the reaction of lithium-titanium ferrite synthesis proceeds in two stages. For the initial mixture (non-milled), mass reduces within the temperature range of 430–720 °C. The results obtained for mechanically activated samples show that mass reduction in these samples begins at much lower temperatures and depends on the time of mechanical grinding. The main mass loss occurs in the temperature range of 420–520 °C with one-step decomposition of lithium carbonate. Thus, the results showed that the reaction of solid-phase interaction of lithium-titanium ferrite proceeds through a two-step mechanism. It is obvious that the reaction mechanism for lithium ferrite synthesis is complex, and it is controlled by diffusion processes. Consequently, a multi-stage model is used to describe the reaction kinetics. For mechanically activated mixtures, the Ginstling-Bronstein model was used at both stages.

Source: Materials Chemistry and Physics - August 27, 2019 Category: Materials Science Source Type: research