HIGH LITHIUM ION CONDUCTIVITY IN THE PEROVSKITE-TYPE COMPOUNDS LN1/2LI1/2TIO3 (LN=LA,PR,ND,SM)

Perovskite-type compounds La0.51(1)Li0.34(1)TiO2.94(2), Pr0.56(2)Li0.34(2)TiO3.01(3), Nd0.55(2)Li0.34(1)TiO3.00(3), and Sm0.52(1)-Li0.38(1)TiO2.97(2) Were synthesized and their structures and lithium ion conductivities were investigated. Symmetry of the lattice changes from cubic for La0.51(1)Li0.34(1)TiO2.94(2) to orthorhombic (space group: Pmmm) for Pr0.56(2)Li0.34(2)TiO3.01(3) and Nd0.55(2)Li0.34(1)TiO3.00(3), and to orthorhombic (Pmma or Pnma) for Sm0.52(1)Li0.38(1)TiO2.97(2). Lithium ion conductivities decrease with decreasing the radii of lanthanide ions, which play the role of spacer for lithium ions.