Growth of Well-Developed Li4Ti5O12 Crystals by the Cooling of a Sodium Chloride Flux

High-quality Li4Ti5O12 crystals were successfully grown at a holding temperature of 800 degrees C and a solute concentration of 50 mol % using the NaCl flux cooling method. Idiomorphic, highly crystalline, and single-phase Li4Ti5O12 crystals were first grown from the NaCl flux; therefore, the method is very low cost and environmentally friendly (i.e., safe for the environment and humans). On the basis of the powder X-ray diffraction data, the lattice parameter of the crystals was determined to be a = 0.838 nm. This value is in good agreement with that from the literature (a = 0.836 nm). The average crystal size was about 2.6 mu m. Transmission electron microscope images indicated that the Li4Ti5O12 crystals had very good crystallinity. In addition, the crystal phase, crystallinity, shape, and size of the flux-grown Li4Ti5O12 crystals were obviously dependent on the growth conditions, such as the holding temperature and solute concentration.