Тип публикации: статья из журнала
Год издания: 2009
Идентификатор DOI: 10.1016/j.solidstatesciences.2008.11.004
Ключевые слова: Oxyfluorides, Phase transition, Calorimetry, Phase diagram, Ferroelectricity, Halide minerals, Phase diagrams, Sugar (sucrose), Thermodynamic properties, Calorimetric measurements, Cubic phase, First-order phase transitions, Heat capacities, Phase transition temperatures, Pressure dependences, Structural transformations, Temperature ranges, Phase transitions
Аннотация: Calorimetric measurements performed in a wide temperature range on (NH4)(3)VO2F4 have shown the presence of four heat capacity anomalies at T-1 = 438 K, T-2 = 244 K, T-3 = 210.2 K, T-4 = 205.1 K associated with the first order phase transitions. In accordance with the permittivity behavior, the structural transformations are of nonПоказать полностьюferroelectric nature. Pressure dependence of the phase transition temperatures has been studied by DTA under pressure. The entropy of phase transitions is analyzed mainly in the framework of the orientational disordering of NH4+ and VO2F43- ions in a cubic phase. (C) 2008 Elsevier Masson SAS. All rights reserved.
Журнал: SOLID STATE SCIENCES
Выпуск журнала: Vol. 11, Is. 4
Номера страниц: 836-840
ISSN журнала: 12932558
Место издания: AMSTERDAM
Издатель: ELSEVIER SCIENCE BV