Phase transitions and vibrational study of (Cs3.5Rb0.5)[(Se0.85S0.15)O3]2[Te(OH)6]3 material

New mixed compound Cs2.8Tl1.2(SO4)1.48(SeO4)0.52.[Te(OH)6]2: Synthesis, structural characterization, vibrational studies and phase transitions

“…The band observed under 119 cm -1 can be ascribed to the vibration and translation modes of (S/SeO  2 4 and TeO  6 6 ) anions [1,24]. In the present work, our assignment agrees well with the previous results of Elferjani et al [1,15,25].…”

“…[Te(OH)6]2 compound exhibits a symmetry space group P21/n with four formula units. It is noteworthy to note that the obtained results pertaining to the TeO6, SO4, SeO4 bands (in Table 3) are in accordance with those obtained in the literature corresponding to the new compound [1,5,16,[24][25][26][27][28][29].…”

“…The crystal structure of the new compound can be easily verified by studying Infrared and Raman spectra at room temperature, which are compared to those found in previous studies about numerous tellurates compounds [1,15,16,24,25]. In fact, the IR and Raman spectra of CsTlSSeTe, recorded for the wavenumber region between (400-4000) and (50-1200) cm -1 , are presented in Figs.…”

“…As for the TeO6 octahedral group, the intense peak located around 673 cm -1 is attributed to the symmetric stretching vibration ν1 of (TeO6), whereas the asymmetric stretching of ν3( TeO6) is found at the wavenumber 596 cm -1 [1,15,24,25].…”

“…Furthermore, these peaks refer to three-phase transitions. In fact, the first peak corresponds to a structural phase transition [1,12,15] and the second one corresponds to the ferroparaelectric phase transition [1,15,24,29]. Moreover, the third one is intense and exhibits the characteristics of a protonic conduction phase transition [1,15,24,30].…”