title: Trithallium hydrogen bis(sulfate), Tl(3)H(SO(4))(2), in the super-ionic phase by X-ray powder diffraction.
abstract: The structure of trithallium hydrogen bis(sulfate), Tl(3)H(SO(4))(2), in the super-ionic phase has been analyzed by Rietveld analysis of the X-ray powder diffraction pattern. Atomic parameters based on the isotypic Rb(3)H(SeO(4))(2) crystal in space group R3m in the super-ionic phase were used as the starting model, because it has been shown from the comparison of thermal and electric properties in Tl(3)H(SO(4))(2) and M(3)H(SO(4))(2) type crystals (M = Rb, Cs or NH(4)) that the room-temperature Tl(3)H(SO(4))(2) phase is isostructural with the high-temperature R3m-symmetry M(3)H(SO(4))(2) crystals. The structure was determined in the trigonal space group R3m and the Rietveld refinement shows that an hydrogen-bond O-H...O separation is slightly shortened compared with O-H...O separations in isotypic M(3)H(SeO(4))(2) crystals. In addition, it was found that the distortion of the SO(4) tetrahedra in Tl(3)H(SO(4))(2) is less than that in isotypic crystals.
authors.affiliation: Department of Applied Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan. ymatsuo@rs.kagu.sut.ac.jp
authors.forename: Yasumitsu
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Shinya
authors.initials: S
authors.lastname: Kawachi
authors.forename: Yuya
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Ikehata