Synthesis, characterization and sintering of Li2TiO3 nanoparticles via low temperature solid-state reaction

Abstract

Synthesis of fine Li2TiO3 powders via low-temperature solid-state reaction (LTSSR) was studied. Solid Li2CO3 and H2TiO3 were blended by planetary ball mill with deionized water as medium. Calcination of the milled powder at low temperature of 500 °C resulted in the formation of pure Li2TiO3 nanoparticles. Another Li2TiO3 powder was also prepared by the conventional solid-state reaction (SSR) and a good comparison between different routes was realized. The results show that the particle size of LTSSR powder is significantly decreased to 19.6 nm while the one obtained by SSR is 146.6 nm. Low temperature calcined powders have less agglomeration and higher sinterability, which can be sintered at lower temperature. Pebbles sintered from the LTSSR powders at 750 °C exhibit small grain size (650 nm), high relative density (85.1%) and satisfactory crush load (42.8 N), whereas the SSR pebbles can only be sintered above 950 °C with the relative density close to 80%. Besides, the LTSSR samples also have a higher conductivity at room temperature, indicating the lower tritium diffusion barrier in ceramics. It is confirmed that H2TiO3 rather than TiO2 is more appropriate for the solid-state reaction to produce Li2TiO3 powders with nano-size particles and favorable properties.