Observations on microstructure and crystal structure of sintered lithium metatitanate with excess Li

Crystal grain growth and crystallization of lithium metatitanate with excess Li (Li2+xTiO3+y), which is expected as an advanced ceramic breeder for a future DEMO fusion reactor, were studied in this paper. By the observation of sintered pellets using scanning electron microscope, it was shown that the Li2.1TiO3+y specimens, which have small grains (1–2 μm) and narrow size distribution, can be obtained by sintering in the temperature range from 1000 to 1100 °C. The observation also showed the rapid grain growth in the Li2.1TiO3 specimens sintered above 1150 °C. The changes in the crystal structure and the phase transformation with the increase of sintering temperature were also investigated by means of powder X-ray diffraction. Finally, the relationship between the grain growth and the phase state at high temperature was discussed.

► The crystal grain growth and crystallization of lithium metatitanate with excess Li (Li2+xTiO3+y), which is expected as an advanced ceramic breeder for a future DEMO fusion reactor were studied in this paper.
► By the observation of sintered pellets using scanning electron microscope, it was shown that the Li2.1TiO3+y specimens which have small grains (1–2 μm) with a slight size distributions can be obtained by sintering in the temperature range from 1000 to 1100 °C.
► The observation also showed the rapid grain growth in the Li2.1TiO3 specimens sintered above 1150 °C.
► The changes in the crystal structure and the phase transformation with the increase of sintering temperature were also investigated by means of powder X-ray diffraction.
► The relationship between the grain growth and the phase state at high temperature was discussed.