The structure of the new protonic conductor,β-Cs3(HSO4)2(H 2-x(P1-x, Sx)O4) (with a superprotonic transition at 125°C), has been determined by single-crystal X-ray diffraction methods. Structural features of this and the related compound,α-Cs3(HSO4)2(H 2PO4), have been further examined by Raman and IR spectroscopy. The new compound crystallizes in space groupC2/c, contains four formula units in the unit cell, and has anxvalue (in the stoichiometry) of approximately 0.5. X-ray intensity data, collected at room temperature, yielded lattice parametersa=20.04(1),b=7.854(5),c=8.954(5) Å, andβ=100.11(2)° and a unit cell volume of 1387.5(14) Å3, implying a density of 3.304 g/cm3. Within the asymmetric unit, 10 nonhydrogen atoms and 3 hydrogen sites were located. Refinement of the X-ray data using anisotropic temperature factors for all 10 of the former yielded residualswR(F2)=0.0952 andR(F)=0.0358. The structure contains alternating zig-zig chains of anion tetrahedra and cesium ions, in a manner similar to that found inα-Cs3(HSO4)2(H2PO 4) and in CsHSO4-II. The structure is unique, however, in that P and S occupy the same crystallographic position, and there is, accordingly, a variable H content and a partially occupied hydrogen bond. Broader peaks in the Raman spectrum ofβ-Cs3(HSO4)2(H2-x(P 1-xSx)O4) support the assumption of greater structural disorder in this compound than inα-Cs3(HSO4)2(H2PO 4).
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry