LITHIUM ION CONDUCTIVITY OF A-SITE DEFICIENT PEROVSKITE SOLID-SOLUTION LA0.67-XLI3XTIO3

La0.67-xLi3xTiO3 solid solution forms in the range approximately 0.15 > x > approximately 0.04 by the substitution mechanism La half arrow right over half arrow left 3Li. Superstructure reflections observed in this range are consistent with a superlattice consisting of the stacking of two perovskite subcells. A line-splitting phenomenon observed for x < approximately 0.1 indicates that the tetragonal distortion of the cubic perovskite subcell occurs. The solid solutions exhibit high lithium ion conductivities greater than 10(-4) S cm-1 at room temperature in a wide range, x > approximately 0.04. A maximum conductivity of 1.1 X 10(-3) S cm-1 is found at x almost-equal-to 0.1. The dome-shaped composition dependence of conductivity indicates that the conduction mechanism involves the movement of lithium ions through the A-site vacancies.