Тип публикации: статья из журнала
Год издания: 2021
Идентификатор DOI: 10.1016/j.jfluchem.2020.109677
Ключевые слова: entropy, fluorides, heat capacity, phase transition, structure, thermal expansion
Аннотация: X-ray, calorimetric and dilatometric studies of K3ZrF7 revealed the existence of the phase transition Fm-3m ↔ R-3m at T0 = 320 K. The structural model assumes a disorder of a pentagonal bipyramid ZrF7 with the following ratio of equivalent orientation positions in the initial and distorted phases: 12 to 6. A good agreement was founПоказать полностьюd between the experimental and model-calculated changes in strain and entropy during the phase transition. A comparative analysis of entropy and structural parameters of related fluorides K3ZrF7 - (NH4)2KZrF7 - (NH4)3ZrF7 was performed. The anomalous behavior of thermodynamic properties in the range 140−230 K is not typical for phase transitions and is accompanied by a significant change in the entropy of the crystal lattice. © 2020 Elsevier B.V.
Журнал: Journal of Fluorine Chemistry
Выпуск журнала: Vol. 241
Номера страниц: 109677
ISSN журнала: 00221139
Издатель: Elsevier B.V.