Тип публикации: статья из журнала
Год издания: 2010
Идентификатор DOI: 10.1088/0953-8984/22/18/185901
Ключевые слова: Antiferromagnets, Ferromagnets, Heat capacities, High stress, Intermediate phase, Pippard relations, Structural phase transition, Transition temperature, Uniaxial pressures, Financial data processing, Phase diagrams, Phase transitions, Thermal stress, Tools, Thermal expansion
Аннотация: The thermal expansion along the a, b and c axes of a (NH4)(2)NbOF5 crystal was measured from 120 to 300 K. Anomalies of alpha(T) associated with previously reported phase transitions Cmc2(1) -> C-2 -> I a were observed along all directions at T-1 = 259.3 K and T-2 = 220.5 K. The analysis of thermal expansion and heat capacity in thПоказать полностьюe frame of the Pippard relations has permitted us to determine the uniaxial pressure derivatives of the transition temperatures dT/d sigma(i). The T-sigma(i) phase diagrams have shown a tendency for the intermediate phase to disappear at high stress along the b and c axes. Intensive and extensive barocaloric effects near the structural phase transitions were found to be comparable with the caloric parameters of some ferroelectrics, ferromagnets and antiferromagnets.
Журнал: JOURNAL OF PHYSICS-CONDENSED MATTER
Выпуск журнала: Vol. 22, Is. 18
ISSN журнала: 09538984
Место издания: BRISTOL
Издатель: IOP PUBLISHING LTD