Effect of Annealing Temperature on the Li\(^{ + }\) Ionic Conductivity of La\(_{0.67 - x}\)Li\(_{3x}\)TiO\(_{3 }\)

Abstract

Abstract. Perovskite La0.67−xLi3xTiO3 with x = 0.10, 0.11, 0.12 and 0.13 were firstly annealed at 800 o C then treated by reactive milling, followed by post-annealing at temperatures from 1100 to 1200 o C. The crystalline structure of grain and grain-boundary were characterized by XRD and SEM. The impedance measurements showed that nanocrystalline La0.67−xLi3xTiO3 after being annealed at 1150 o C possessed a grain conductivity as high as 1.3 × 10 −3 S.cm −1 . The grainboundary conductivity was enhanced one order in magnitude after annealing at temperature higher 1100˚C and consists of 5.8 × 10 −5 S.cm −1 . The results have also showed the limitation of the adiabatic thermal treatment for the improvement of the grain-boundary conductivity and suggested the way to overcome the limitation by rapidly cooling the samples from the high temperature to room temperature.