Mhiri Tahar,Khouloud Ghorbel, Lilia Ktari and Mohamed Dammak
Solid State Chemical Physical Laboratory, Faculty of Science of Sfax, University of Sfax, Sfax, Tunisia
The crystal structure of (NH4)2(SO4)0.86H (PO4)0.14.Te (OH)6 [NSPTe] crystallizes in the monoclinic system P21/c with a = 13.704(5) Å, b = 6.616(2) Å, c = 11.386(2) Å, β = 106.751(4)° and Z = 4. The structure is formed by a set of anions (Te, S and HP) and N groups connected by two types of hydrogen bonds O-H…O and N-H…O which make the building of the crystal. The differential scanning calorimetry (DSC) analysis has shown three-phase transitions before the decomposition at 373 K, 398 K and 413 K. The thermal analyses (DTA) and (TG) of the title compound has proven that the decomposition of this material starts at a temperature equal to 450 K. The Raman spectroscopy at various temperatures, it has confirmed the presence of the phase transitions shown in DSC and DTA. The vibrational study at room temperature shows the presence and the independence of anionic groups, ammonium groups and gives more importance to the strong hydrogen bonds.
Keywords: Nano material, Chemistry Biotechnology, structure.