Kalkuta S. Theoretical study of a crystal structure and electronic structure of an ionic conductor of La0.5Li0.5TiO3

Researches are carried out by high-precision ab-initio method (FLAPW). On the basis of the performed calculations, it is determined that the ordering in layers of lanthanum atoms and location of the lithium ions in the centers of verges of cubes, formed by the atoms of titan are energy advantageously. The analysis of number of lithium vacancies participating in ionic conductivity is carried out. The possible ways of diffusion of lithium ion in La0.5Li0.5TiO3 grate are studied by the ab-initio method. The comparison with experimental data is made. Taking into account the simulation results of atomic build of La0.5Li0.5TiO3 compound, it is suggested to optimize the effect ionic conductivity of this compound by means of partial substitution of the lanthanum atoms to the cerium ones. This compound is a dielectric and must be a lithium conductor. Dependences of number of lithium vacancies from concentration of lithium ions at different temperatures in hypothetical LaxCe0.5-xLixTiO3 compound and in La(2-x)/3LixTiO3 compound was calculated by the Monte-Carlo method. It is determined that the number of lithium vacancies participating in conductivity is essentially more in LaxCe0.5-xLixTiO3.