Non-stoichiometry and its effect on thermal properties of Li2TiO3

Li2TiO3 is among the most promising candidates for solid breeder materials. However, its structural property, especially the possibility of non-stoichiometric composition, has not been well established yet. Therefore, the composition of Li2TiO3 has been further investigated by means of thermogravimetry, XRD etc. Also, thermal diffusivity measurement was carried out. Mass of Li2TiO3 was found to change after the change of the atmosphere from hydrogen to oxygen as observed by means of thermogravimetry. At the same time, the color was observed to change from dark blue to initial color, white. These behaviors suggest not only oxygen deficient but also lithium oxide deficient defects formation. Thus, the doubly non-stoichiometric composition, Li2−xTiO3−y, has been confirmed. Further, it was shown by thermal diffusivity measurement that 95Li2TiO3 (i.e. Li2O/TiO2=0.95) has a higher thermal conductivity than 100Li2TiO3.