Synthesis and investigation of the structure, thermal and electrical properties of new Tl5-xKxLuZr(MoO4)6 (x = 0; 0.1; 0.2; 1; 2) molybdates

The traditional solid-state synthesizing method was employed to prepare Tl_5-xK_xLuZr(MoO₄)₆ (x = 0; 0.1; 0.2; 1; 2) ceramics. Structural characterization was performed through the Rietveld method on the X-ray powder diffraction data. The unit cell parameters are defined for Tl_5-xK_xLuZr(MoO₄)₆ (x = 0; 0.1; 0.2; 1; 2). Impedance spectra were measured at temperatures ranging from 300 to 800 K, covering a frequency range of 1 Hz to 1 MHz. The results show that the electrical conductivity decreases with an incrementing in the x value in the range of x = 0.1–2.0. Tl_4.9K_0.1LuZr(MoO₄)₆ has the best ionic conductivity of this series of molybdates (1.31 × 10⁻³ S cm⁻¹₎, and Tl₅LuZr(MoO₄)₆ has the lowest conductivity (5.51 × 10⁻⁴ S cm⁻¹₎. Activation energy was found out to decrease from 1.32 eV for Tl₅LuZr(MoO₄)₆ to 0.92 eV for Tl_4.9K_0.1LuZr(MoO₄)_6.