Study of the ionic conductivity of Li0.5La0.5TiO3 laser-sintered ceramics

This work explores a chemical synthesis route and, for the first time, laser processing of ionic conductor Li0.5La0.5TiO3 (LLTO) ceramics. The laser sintering technique has been efficient in producing highly dense singlephase ceramics in just a few minutes, starting from an amorphous precursor powder. As comparison, conventionally sintered ceramics were also prepared. Both methods yield polycrystals with long-range structure compatible with a single cubic perovskite, as confirmed by Rietveld refinement of the powder XRD pattern. In contrast, Raman spectroscopy has revealed non-cubic symmetry, indicating the formation of ordered nanodomains. At room temperature, high ionic conductivity of similar to 0.5 mS/cm was achieved for the bulk of laser and conventionally sintered samples. However, the grain boundary conductivity changed from 1.10(-3) mS.cm(-1) (laser-sintered) to 6.10(-3) mS.cm(-1) (conventionally sintered), which was attributed to changes in the micro structural characteristics of the ceramics.