Non-stoichiometory and vaporization characteristic of Li2.1TiO3.05 in hydrogen atmosphere

Lithium titanate (Li2TiO3) is one of the most promising candidates among the proposed solid breeder materials in fusion reactors because of its chemical satiability. Addition of H2 to inert sweep gas has been proposed for enhancing the release of bred tritium from breeder material. However, the mass of Li2TiO3 has been found to decrease with time in the hydrogen atmosphere. In order to control the mass change at the time of high-temperature use, development of Li2TiO3 which has excess Li2O is needed. Li2TiO3 (L100) and Li2.1TiO3.05 (L105) were prepared by solid-state reaction at 1273 K of Li2CO3 and TiO2 powders. In thermogravimetry, the masses of samples L100 and L105 were found to decrease with time in a hydrogen atmosphere, then to increase after a change of the atmosphere from hydrogen to oxygen. Sample L105 has fewer oxygen defects than L100. An atmosphere-controlled high-temperature mass spectrometer has provided the vapor pressure data for L100 and L105, under the conditions of D2 atmospheres. Sample L105 has a higher partial pressure of total Li-containing species than L100 above 1093 K.