A novel synthetic route of garnet-type Li_6.5La₃Zr_1.5Ta_0.5O₁₂ using pyrochlore-type La₂Zr₂O₇ and weberite-type La₃TaO₇ as starting materials

Abstract

We successfully synthesized a garnet-type Li_6.5La₃Zr_1.5Ta_0.5O₁₂ polycrystalline sample at a relatively low temperature of 700°C using pyrochlore-type La₂Zr₂O₇ and weberite-type La₃TaO₇ as precursor oxides. The cubic garnet-type structure with the lattice parameter of a = 1.29577(1) nm was confirmed using powder X-ray diffraction data. The primary particle size of the present Li_6.5La₃Zr_1.5Ta_0.5O₁₂ sample was about 2 µm, which is considerably smaller than that prepared using conventional solid-state reaction at higher temperatures. Thermogravimetry differential thermal analysis data confirmed that the reaction between LiOH·H₂O and precursor oxides occurred above 500°C after the dehydration reaction of LiOH·H₂O.