High ionic conductivity of K5-xTlx(Mg0.5Hf1.5)(MoO4)6 (0 ≤ х ≤ 5) solid solutions

Grossman, V.G., Molokeev, M.S., Bazarova, J.G., Bazarov, B.G.// Solid State Sciences//

https://doi.org/10.1016/j.solidstatesciences.2022.107027

Novel K5-xTlx(Mg0.5Hf1.5)(MoO4)6 (0 ≤ х ≤ 5) oxides were successfully synthesized by solid state reaction. The results indicate the formation of a continuous series of solid solutions with the NASICON-like structure (sp. gr. R $\overline{3}$ c) in the composition range 0 < x < 5. The unit-cell parameters of the solid solutions increase linearly with composition, as a consequence of thallium substitution for potassium. The cation conductivity of Tl5Mg0.5Hf1.5(MoO4)6 has been shown to exceed the conductivity of the parent potassium magnesium hafnium molybdate. The highest total conductivity of 2.49 × 10−3 S/cm was found at 831 K for Tl5Mg0.5Hf1.5(MoO4)6.