Environmentally Friendly Flux Growth of High-Quality, Idiomorphic Li₅La₃Nb₂O₁₂ Crystals

High-quality, idiomorphic, single-phase Li₅La₃Nb₂O₁₂ crystals were successfully grown using a LiOH flux cooling method at the relatively low temperature of 500 °C at a solute concentration of 5 mol %. The grown Li₅La₃Nb₂O₁₂ crystals had polyhedral shapes with well-developed, flat {211} and {110} faces. Their shapes were relatively uniform, and the average crystal size was approximately 59.2 μm. No aggregation was observed in scanning electron microscopy images. The high crystallinity of the Li₅La₃Nb₂O₁₂ crystals was confirmed by transmission electron microscopy images. Their lattice parameter was determined from the X-ray diffraction pattern to be <i>a</i> = 1.281 nm, which is consistent with the literature value (<i>a</i> = 1.282 nm). Furthermore, the crystal phase, form, size, and crystallinity of the flux-grown Li₅La₃Nb₂O₁₂ crystals were obviously dependent on the growth conditions including the solute concentration and holding temperature