Non-stoichiometry of Li2TiO3 under hydrogen atmosphere condition

Li2TiO3 is one of the most promising candidates for solid breeder materials. In order to control the grain growth at the time of high temperature use, the development of Li2TiO3 which has oxide additive is needed. In the present paper, the structure and the non-stoichiometry of Li2TiO3 added with some different oxides have been extensively investigated by means of thermogravimetry and X-ray diffractometry (XRD). In the case of the Li2TiO3 samples used in this study, Li2TiO3 powder and oxide powder (CaO, ZrO2, Sc2O3) in small quantity were mixed in the following molecular ratio: CaO/Li2TiO3 = 0.20%, ZrO2/Li2TiO3 = 0.44% or Sc2O3/Li2TiO3 = 0.40%. These samples are designated as Ca–Li2TiO3, Zr–Li2TiO3, and Sc–Li2TiO3, respectively. Ca–Li2TiO3 and Zr–Li2TiO3 exist as double phases, and Sc–Li2TiO3 exists as a single phase. In thermogravimetry, Ca–Li2TiO3 has fewer oxygen defects than the other kinds of Li2TiO3 in the hydrogen atmosphere. The overall results suggest that the oxide additives are able to control not only the growth of the grain size but also the amount of oxygen defects.