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

Novel K5-xTlx(Mg0.5Hf1.5)(MoO4)(6) (0 <= x <= 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 (3) over barc) 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 x 10(-3) S/cm was found at 831 K for Tl5Mg0.5Hf1.5(MoO4)(6).

Automated summary

A series of novel potassium-thallium silicotungstate oxides were successfully synthesized by solid state reaction, showing a continuous solid solution series with increasing unit-cell parameters linearly with composition due to thallium substitution for potassium. The highest total conductivity was found for Tl5Mg0.5Hf1.5(MoO4)(6) at 831K, exceeding the parent potassium magnesium hafnium molybdate.