Thermal, structural, optical, dielectric and barocaloric properties at ferroelastic phase transition in trigonal (NH4)(2)SnF6: A new look at the old compound
Скачать файл:
URI (для ссылок/цитирований):
https://elib.sfu-kras.ru/handle/2311/33075Автор:
Флёров, И. Н.
Карташев, А. В.
Горев, М. В.
Богданов, Е. В.
Мельникова, С. В.
Молокеев, М. С.
Погорельцев, Е. И.
Лапташ, Н. М.
Коллективный автор:
Институт инженерной физики и радиоэлектроники
Кафедра теплофизики
Дата:
2016-03Журнал:
Journal of Fluorine ChemistryКвартиль журнала в Scopus:
Q2Квартиль журнала в Web of Science:
Q2Библиографическое описание:
Флёров, И. Н. Thermal, structural, optical, dielectric and barocaloric properties at ferroelastic phase transition in trigonal (NH4)(2)SnF6: A new look at the old compound [Текст] / И. Н. Флёров, А. В. Карташев, М. В. Горев, Е. В. Богданов, С. В. Мельникова, М. С. Молокеев, Е. И. Погорельцев, Н. М. Лапташ // Journal of Fluorine Chemistry. — 2016. — Т. 183. — С. 1-9Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.
Аннотация:
Structural phase transition P-3m1 <-> P-1 of the first order and nonferroelectric nature was found in (NH4)(2)SnF6 at about 110 K in the process of thermal, optical, dielectric and X-ray studies. Order-disorder transformation is accompanied by large changes of entropy (Delta S-0 = 16.4J/mol K) and volume (Delta V-0/V approximate to 1%). The structural model associated with three orientations of NH4 tetrahedra in P-3m1 phase and their complete ordering in P-1 phase was suggested with the entropy change (Delta S-0 = 18.3 J/mol K) close to the experimental value. A good agreement between baric coefficients measured in a direct way (dT(0)/dp = -157 K/GPa) and evaluated using entropy and volume changes at phase transition (-170 K/GPa) was found. Barocaloric effects in (NH4)(2)SnF6 are comparable with those of known solid state refrigerants and are characterised by a low-pressure need for realising their maximum values.