Cation distribution and diffusion-path topologies of A-site-deficient perovskite Li_xLa_(1−x)/3NbO₃

Abstract

Li_xLa_(1−x)/3NbO₃ with an A-site-deficient perovskite structure was investigated with a focus on the relationship between its atomic configuration and Li⁺ diffusion properties. To this end, total scattering (diffraction) measurements were performed, and then reverse Monte Carlo modeling using the data was employed to construct the atomic configuration. The results suggest that the partial occupancy of La in the La-poor layer facilitate Li⁺ diffusion across the layer owing to the volume contraction. Furthermore, topological analyses conducted via persistent homology using the constructed atomic configuration indicate that a large fourfold ring formed by Nb and O is one of the reasons for superior Li⁺ diffusion in Li_xLa_(1−x)/3NbO₃.