Lowering Ternary Oxide Synthesis Temperatures by Solid-State Cometathesis Reactions

Low-temperature synthesis routes are necessary for selectively synthesizing many metastable solid-state materials. Here, we identify a cooperative effect that starting materials have in lowering temperatures metathesis reactions by studying the formation of yttrium manganese oxide. Previous studies shown YMnO3 can be synthesized ternary with an alkali halide being produced as secondary product. In this contribution, show using alkaline earth metals instead metals, polymorph selectivity reaction is changed, orthorhombic forms at lower than hexagonal polymorph. Reactions were studied ex post facto synchrotron X-ray diffraction. These experiments reveal oxides material require high to progress. Reaction lowered from 700 550 °C while maintaining phase reacting both MgMn2O4 and CaMn2O4 YOCl “cometathesis” reaction. The nascent salts appear improve kinetics. Since onset temperature falls 50 below MgCl2–CaCl2 liquidus, enhanced reactivity consistent surface melting nasscent salt byproduct interfaces. Cometathesis similar reduction form TbMnO3, ErMnO3, DyMnO3. lowers preserving end members, making it valuable approach targets.