Interdisciplinary Graduate School of Engineering Sciences, Kyushu University
Abstract
Self－diffusion coefficients of the oxygen ion in antifluorite-cubic Li_2O were determined by means of the gas-solid isotope exchange and solid-phase analysis technique using ^<18>O as the tracer. The lattice diffusion coefficient was estimated by utilizing the relationship between grain-size and particl-size dependences of the apparent diffusion coefficients determined for polycrystalline samples. Diffusion characteristics of the constituent ions in antifluorite-cubic crystals were discussed in comparison with those in fluoritecubic crystals. The ionic conductivity for Li_2O was discussed in terms of the diffusivities of both constituent ions
