Vaporization property and crystal structure of lithium metatitanate with excess Li

The vaporization property and the crystal structure of lithium metatitanate with excess Li, which has been developed as an advanced tritium breeder, were studied. After synthesizing the lithium metatitanate specimens with Li/Ti = 2.0–2.3 (at mixing of the starting materials), the vaporization properties were investigated by measuring the mass losses during heating at 1173 K. The Li excessive specimens indicated higher rates of mass loss than the stoichiometric one during heating as long as excessive lithium atom exists. The crystal structures of stoichiometric and nonstoichiometric lithium metatitanates were discussed with the result of neutron diffraction and the refined structural parameters by Rietveld analysis. The refinement (Rwp = 7.98, Rp = 5.96 and Re = 2.58) suggested that lithium metatitanate with excess Li has β-Li2TiO3 structure and excess Li atoms exist at unstable sites with the formation of reduced titanium or site vacancies.