Synthesis, calorimetric, structural and conductivity studies in a new thallium selenate tellurate adduct compound

Crystals of Tl2SeO4·Te(OH)6 undergo three endothermal transitions at 373, 395 and 437 K. These transitions are detected by DSC and analyzed by dielectric measurements with impedance spectroscopy. The evolution of conductivity versus temperature showed the presence of a protonic conduction phase transition at 437 K. The phase transition at 373 K can be related to a structural phase transition, whereas the one at 395 K is ascribed as likely due to a ferroelectric-paraelectric phase transition.