Calorimetric, dilatometric and DTA under pressure studies of the phase transitions in elpasolite (NH4)2KZrF7

Описание

Тип публикации: статья из журнала

Год издания: 2020

Идентификатор DOI: 10.1016/j.jfluchem.2020.109523

Ключевые слова: Entropy, Fluorides, Heat capacity, High pressure, Phase transition, Thermal expansion

Аннотация: Heat capacity, thermal expansion, and sensitivity to the hydrostatic pressure of (NH4)2KZrF7 elpasolite are studied in a wide temperature range. The changes in deformation and entropy during successive phase transitions are determined: Δ(ΔV/V) = 3·10−4; ΔS = 8 J/mol K The temperatures and entropies of phase transitions turned out tПоказать полностьюo be slightly sensitive to pressure changes. An analysis of the entropy of phase transformations was performed in the framework of the model of the cubic phase structure Fm-3 m. In the low temperature phase, an anomalous behavior of thermodynamic properties, which is not characteristic of phase transitions, was observed, accompanied by a significant change in the crystal lattice entropy. © 2020 Elsevier B.V.

Ссылки на полный текст

Издание

Журнал: Journal of Fluorine Chemistry

Выпуск журнала: Vol. 235

Номера страниц: 109523

ISSN журнала: 00221139

Издатель: Elsevier B.V.

Персоны

  • Gorev Mikhail (Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Krasnoyarsk 660036, Russia; Siberian Fed Univ, Inst Engn Phys & Radioelect, Krasnoyarsk 660074, Russia)
  • Kartashev Andrey (Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Krasnoyarsk 660036, Russia; Astafijev Krasnoyarsk State Pedag Univ, Krasnoyarsk 660049, Russia)
  • Bogdanov Evgeniy (Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Krasnoyarsk 660036, Russia; Krasnoyarsk State Agr Univ, Inst Engn Syst & Energy, Krasnoyarsk 660049, Russia)
  • Flerov Igor N. (Fed Res Ctr KSC SB RAS, Kirensky Inst Phys, Krasnoyarsk 660036, Russia; Siberian Fed Univ, Inst Engn Phys & Radioelect, Krasnoyarsk 660074, Russia)
  • Laptash Natalia M. (Far Eastern Dept RAS, Inst Chem, Vladivostok 690022, Russia)