Thermal behavior and physicochemical studies of phase transitions before the decomposition in the selenate-tellurate protonic conductor material

Thermal analysis confirmed the presence of the phase transition at T = 320 K in the Cs2SeO4 center dot H6TeO6 (CsSeTe) material. The structural study carried out at T = 360 K shows that this compound passes from the monoclinic system with the space group P2(1)/c at room temperature, to the trigonal system with the space group R $(3) over bar $m. At room temperature, the anionic groups are well ordered and stable, whereas after the transition at T = 320 K, the selenate groups change their orientation and the tellurate polyhedra change their positions. The high-temperature vibrational studies, carried out in a temperature range of 289-353 K, confirm the presence and nature of the transition detected by thermal analysis. The conductivity evolution versus temperature shows the presence of an ionic-protonic conduction phase transition at T = 490 K.

Automated summary

Thermal analysis confirmed the phase transition at T = 320 K in the Cs2SeO4·H6TeO6 (CsSeTe) material, with structural study showing a transition at T = 360 K and conductivity evolution indicating an ionic-protonic conduction phase transition at T = 490 K.