Crystal Structure of a Lithium Ion-Conducting Perovskite La2/3-xLi3xTiO3 (x=0.05)

The crystal structure of a lithium ion-conducting perovskite La0.62(2)Li0.16(1)TiO3.01(3) obtained by furnace-cooling was refined by the Rietveld method using neutron-diffraction data at room temperature and 77 K. The adopted space group was Cmmm (No. 65). The anti-phased tilts of TiO6 octahedra along the b-axis in addition to alternative arrangement of La ions along the caxis was confirmed. The position of Li was refined to be off-centered and in two equivalent positions in an A-site. The obtained structural information implies that the lithium ion conduction among A-sites occurs in the vicinity of La-poor layers twodimensionally rather than three-dimensionally in this compound.