Metastable formation of low temperature cubic Li2TiO3 under hydrothermal conditions — Its stability and structural properties

Cubic Li2TiO3 samples (space group Fm-3m) were synthesized by hydrothermal reactions at 180 °C for 18 h, using titania powder and lithium hydroxide in de-ionized water. The samples were found to be unstable under atmospheric conditions as Li2CO3 could be detected by X-ray powder diffraction (XRPD) on their surface. Therefore, the stability of cubic Li2TiO3 when exposed to water was investigated. In water-flushing and bathing experiments the interaction of water with the samples could be demonstrated. The observed lithium loss was analyzed by atomic absorption spectroscopy and its influence on the structural properties of cubic Li2TiO3 was determined by conventional XRPD and multi-temperature synchrotron XRPD.