Structural, thermal and electrical studies of thallium-scandium-hafnium(zirconium) molybdates

Thallium scandium hafnium molybdate Tl5ScHf(MoO4)(6) and thallium scandium zirconium molybdate Tl5ScHf(MoO4)(6) crystallize in trigonal symmetry with the space group R (3) over barc. The compounds are synthesized by sintering the finely powdered simple molybdates mixture in a muffle furnace at 723-823 K for 100 h. The crystal structures of Tl5ScHf(MoO4)(6) and Tl5ScHf(MoO4)(6) are obtained by Rietveld method. The following unit cell parameters are calculated for Tl5ScHf(MoO4)(6) : a = 10.62338 (5), c = 38.0579 (2) angstrom, V = 3719.64 (4) angstrom(3), Z = 6 and for Tl5ScHf(MoO4)(6) : a = 10.63216 (7), c = 38.0716 (3) angstrom, V = 3727.14 (5) angstrom(3), Z = 6. The conductivity of the Tl5ScHf(MoO4)(6) and Tl5ScHf(MoO4)(6) are measured between 293 and 860 K. The ionic conductivity of Tl5ScHf(MoO4)(6) and Tl5ScHf(MoO4)(6) molybdates are 8 x 10(-4) S/cm and 8 x 10(-3) S/cm (at 773 K); the activation energy of ionic transfer are 0.8 eV and 0.3 eV respectively.

Automated summary

Thallium scandium hafnium molybdate and thallium scandium zirconium molybdate crystallize in trigonal symmetry with the space group R (3) over barc. The crystal structures were obtained by Rietveld method, and the ionic conductivities were measured at different temperatures. The results showed that the molybdates have different ionic conductivities at 773K, with activation energies of 0.8 eV and 0.3 eV respectively.