Crystal structure change of Li2+xTiO3+y tritium breeder under moist air

Abstract To investigate the aging behavior of Li 2+ x TiO 3+ y , the materials Li 2.0 TiO 3+ y , Li 2.2 TiO 3+ y and Li 2.4 TiO 3+ y were stored under moist air at ambient temperature. Under these conditions the weight of Li 2.0 TiO 3+ y increased by only 1% in 100 days, which provides evidence for the high chemical stability of Li 2 TiO 3 . In comparison, under the same storage conditions the weights of Li 2.2 TiO 3+ y and Li 2.4 TiO 3+ y increased by 14% and 18%, respectively. The observed weight gain is attributed to the uptake of water, and to the reaction of a by-product of Li 2+ x TiO 3+ y with water and carbon dioxide. The weight gain curves were evaluated by the Jander equation. From the analysis, it was possible to obtain the diffusion coefficient of water through Li 2 TiO 3 particles at ambient temperature. The determined value was 2 × 10 −17 m 2 /s.