Тип публикации: статья из журнала
Год издания: 2014
Идентификатор DOI: 10.1016/j.jfluchem.2014.10.016
Ключевые слова: Cubic fluorides, Phase transitions, Dielectric, Phase diagram, Calorimetry
Аннотация: Successive phase transitions G1 --> G2 --> G3 in the double salt (NH4)(3)TiF7 have been studied by detailed calorimetric, DTA under hydrostatic pressure and dielectric measurements. Rather large entropy jumps at phase transition points were found to be followed by large additional contributions associated with the temperature depenПоказать полностьюdence of the excess heat capacity. The permittivity behaviour and the tangent of the dielectric losses proved the nonferroelectric nature of both transformations. Two triple-points were found on the temperature-pressure phase diagram, suggesting the existence of a hypothetical parent G0 = Pm-3m cubic phase. A direct transformation between high (G0) and low (G3) temperature cubic phases takes place at p > 0.41 GPa with a baric coefficient dT(G0) --> (G3)/dp = -40 K/GPa. (C) 2014 Elsevier B.V. All rights reserved.
Журнал: JOURNAL OF FLUORINE CHEMISTRY
Выпуск журнала: Vol. 168
Номера страниц: 247-250
ISSN журнала: 00221139
Место издания: LAUSANNE
Издатель: ELSEVIER SCIENCE SA