University of Tsukuba, AIST^* AIST^** University of Tsukuba^***
○Kunimitsu Kataoka^* Yasuhiko Takahshi^** Norihito Kijima^** Junji Akimoto^** Ken-ichi Ohshima^***

Single crystal growth and structural characterization of Li₄Ti₅O₁₂ were originally determined by Deschanvres et al. in 1971 [1]. However, the precise structural properties have not been determined yet. In the present study, we report crystal and electronic structures of Li₄TI₅O₁₂ using the single-crystal X-ray diffraction data.
Single crystals of the spinel-type Li₄Ti₅O₁₂ were growth by a flux method. A colorless octahedral-shaped crystal was obtained, as shown in the figure. The crystal structure and electron density distribution of the Li₄Ti₅O₁₂ have been studied by X-ray structure analysis and maximum entropy method (MEM) using single-crystal X-ray diffraction data at room temperature. The cubic lattice parameter (a = 8.355(4) Å), determined by a least-squares refinement using 25 strong reflections, and the space group Fd-3m have been confirmed by the present single-crystal X-ray diffraction data. The structure was refined to the conventional values of R = 3.3% and wR = 5.4% using 209 independent reflections. From the results of the single-crystal MEM analysis, a strong covalent bonding was clearly found between the Ti and O atoms in Li₄Ti₅O₁₂.
[1] A. Deschanvres, B. Raveau and Z. Sekkal, Mat. Res. Bull. 6, 699, (1971)