SOLID-STATE SYNTHESIS OF STABLE SUBSTANCES Li-Mn-O SYSTEM.

By employing thermal, X-ray diffraction and chemical analysis, we study chemical reactions, which occur at heating manganese oxide (MnO₂ ) with lithium carbonate ( Li₂CO₃) on air. We reveal that only three thermodynamically stable substances - manganese (III) oxide (Mn₂O₃), lithium manganate ( Li₂MnO₃) and mixed oxide LiMn₂O₄ with spinel structure - can be formed at 700-900 °C temperature ranges. Many other known substances of Li-Mn-O system are unstable under these conditions and cannot be obtained by solid-state methods. [ABSTRACT FROM AUTHOR]