Structural, dielectric and vibrational studies in the dipotassium sulfate selenate tellurate mixed solid solution

Dehydration and decomposition behavior of the NaH2(PO4)0,48AsO4)0,52.H2O compound in the temperature range from 253 K to 333 K.

“…This transformation may be accredited to changes in hydrogen bonds. This hypothesis is confirmed by the analysis of the spectra of X-ray diffraction powder that shows a change in the number and the location of some diffraction peaks [15,17]. J u l y 31, 2 0 1 4…”

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

“…In fact, the most intense peaks around 650 cm -1 in Raman can be assigned to ν 1 (TeO 6 ), the vibration mode ν 2 (TeO 6 ) is distinguished by the medium Raman band at about 631cm -1 . Moreover, the two peaks detected at 366 cm -1 and 388 cm -1 correspond to ν 4 (TeO 6 ) vibration mode [17,20,21], while the medium bands at 341 and 346 cm -1 are attributed to the ν 5 vibration mode of (TeO 6 ) and the Raman peak around 221 cm -1 may be assigned to ν 6 (TeO 6 ).…”

“…The ν 1 mode is the totally symmetric stretching vibrational mode of the SeO 4 anion, ν 2 is the doubly asymmetric degenerate bending mode, ν 3 is the triply symmetric degenerate stretching mode and ν 4 is the triply asymmetric degenerate bending mode[18]. The very strong peak around 824 cm -1 may be assigned to ν 1 (SeO 4 ) vibration mode, the line observed at 845 cm -1 can be attributed to the ν 3 (SeO 4 ) vibration mode, while the three peaks observed at 388, 405 and 420 cm -1 are related to the triply degenerate bending mode ν 4 (SeO 4 )[22,23].The broad peaks at 439, 449 and 452 are tentatively assigned to the doubling degenerate bending vibration mode ν 2 (SeO 4 ), as it detects by the intense band with frequency at 319 cm -1[17,20,21]. The tetrahedral SeO 4 group has all the vibration modes which are infrared active, whereas only ν 1 is inactive.…”

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

“…So far, the most important structural property of these crystals is the presence of some anionic groups (TeO  6 6 , SO  2 4 and SeO  2 4 ) in the unit cell. Overall, another key feature of these compounds pertains to the hydrogen bonds, formed in their crystal structure, which represents further evidence for the significance of such family [11][12][13][14][15][16].…”

“…What is worthwhile to note is that these are structural transitions in terms of discovering physical properties, including ferroelectricity and superionic-protonic conduction, referring principally to the motion of the proton H + via the hydrogen bonds [1,5,10,[14][15][16].…”