Phase States in the Li–Mn–Eu–O System

Polycrystalline samples of the Li–Mn–Eu–O system were obtained by preliminarily ball-milled precursor mixtures annealing in air (700, 800, 900, 1000, and 1100°C). The obtained products were studied by X-ray powder diffraction and thermogravimetry (TG-DSC). The possibility of substituting Mn with Eu for spinel LiMn 2– x Eu x O 4 was assessed. Within the framework of the Li–Mn–Eu concentration triangle, a subsolidus isobaric diagram and a projection of the liquidus surface of the Li–Mn–Eu–O system were constructed using models of polythermal phase diagrams of the LiEuO 2 –LiMnO 2 and LiEuO 2 –LiMn 2 O 4 sections. The temperatures of eutectic equilibria involving three crystalline phases and a melt were determined.