Sequence of phase transitions in (NH4)3SiF7

Описание

Тип публикации: статья из журнала

Год издания: 2017

Идентификатор DOI: 10.1039/c6dt04874a

Ключевые слова: Group theory, Single crystals, X ray diffraction, Atomic displacement, Double salts, Driving forces, Group-theoretical analysis, Order parameter, Polarization optics, Temperature changes, Hydrogen bonds

Аннотация: Single crystals of silicon double salt (NH4)3SiF7 = (NH4)2SiF6·NH4F = (NH4)3[SiF6]F were grown and studied by the methods of polarization optics, X-ray diffraction and calorimetry. A sequence of symmetry transformations with the temperature change was established: P4/mbm (Z = 2) (G1) - Pbam (Z = 4) (G2) - P21/c (Z = 4) (G3) - P1 (ZПоказать полностью= 4) (G4) - P21/c (Z = 8) (G5). Crystal structures of different phases were determined. The experimental data were also interpreted by a group-theoretical analysis of the complete condensate of order parameters taking into account critical and noncritical atomic displacements. Strengthening of the N-H?F hydrogen bonds can be a driving force of the observed phase transitions. © The Royal Society of Chemistry.

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Издание

Журнал: Dalton Transactions

Выпуск журнала: Vol. 46, Is. 8

Номера страниц: 2609-2617

Персоны

  • Mel'nikova S.V. (Laboratory of Crystal Physics, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, Russian Federation)
  • Molokeev M.S. (Laboratory of Crystal Physics, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, Russian Federation, Department of Physics, Far Eastern State Transport University, Khabarovsk, Russian Federation)
  • Laptash N.M. (Institute of Chemistry, Far Eastern Branch of RAS, Vladivostok, Russian Federation)
  • Pogoreltsev E.I. (Laboratory of Crystal Physics, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, Russian Federation, Siberian Federal University, Krasnoyarsk, Russian Federation)
  • Misyul S.V. (Siberian Federal University, Krasnoyarsk, Russian Federation)
  • Flerov I.N. (Laboratory of Crystal Physics, Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, Russian Federation, Siberian Federal University, Krasnoyarsk, Russian Federation)