Dynamical properties and electronic structure of (LaLi)TiO3 conductors

A computer simulation by a molecular dynamics method is performed to study the properties of structure and Li ion diffusion in La_4/3???x Li (LaLi)TiO₃ ;LLTO;Li ion conductors;Superionic conductors;Perovskite;Off-site;Electronic structureA computer simulation by a molecular dynamics method is performed to study the properties of structure and Li ion diffusion in La_{4/3 − x} Li Ti₂O₆ =(LaLi)TiO₃ =LLTO, which is the perovskite-type Li ion conductor. In the low Li concentration, Li ions conduct a two-dimensional motion, while Li ions diffuse a three-dimensional motion in the high Li ion concentration. The partial distribution function for Li–Ti and the diffusion paths of Li ions suggest that Li ions stay for a long time at off-site positions, which are 2.7? away from a body-centered Ti ion. The Li ion concentration dependence to the conductivity σ is in approximate agreement with experiments. The energy band dispersion and the density of states are calculated using the linear-muffin-tin-orbital method. The energy contour map shows the stable position of Li ions is off center of the vacant La sites. Both calculations suggest that the stable position of Li ions is off center of the vacant La sites. Paper presented at the 11th EuroConference on the Science and Technology of Ionics, Batz-sur-Mer, Sept. 9–15, 2007.