Abstract
La0.61Li0.17TiO3 microstructures have been studied by high resolution electron microscopy. A local lattice distortion occurs in the vicinity of the domain boundary region due to the twin with an angle of 89°. The average domain size of La0.61Li0.17TiO3 is greater than 20 nm. The domain size and structures of La0.61Li0.17TiO3 differ greatly from those of La-poor compounds, such as La0.55Li0.35TiO3. At a nanoscopic level, microdomains of 20–100 nm in size construct a two-dimensional structure in La-rich compounds, while microdomains of 5–10 nm in size construct a three-dimensional structure in La-poor compounds. In addition, the Li-ion conduction mechanisms for La-rich and La-poor compounds are two- and three-dimensional, respectively.
Acknowledgements
The authors thank Emeritus Professor K. Hiraga of Tohoku University for his useful advice. This work was supported by the Center for Integrated Nanotechnology Support at Tohoku University and the Grant-in-Aid for Scientific Research on Priority Area, ‘Nanoionics (439)’ of Ministry of Education, Culture, Sports, Science and Technology, Japan.