Thermal expansion, phase diagrams and barocaloric effects in (NH4)(2)NbOF5

Описание

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.

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Издание

Журнал: JOURNAL OF PHYSICS-CONDENSED MATTER

Выпуск журнала: Vol. 22, Is. 18

ISSN журнала: 09538984

Место издания: BRISTOL

Издатель: IOP PUBLISHING LTD

Персоны

  • Gorev Michail (Russian Acad Sci, Siberian Div, LV Kirensky Phys Inst, Krasnoyarsk 660036, Russia; Siberian Fed Univ, Inst Engn Phys, Krasnoyarsk 660041, Russia)
  • Bogdanov Evgeny (Russian Acad Sci, Siberian Div, LV Kirensky Phys Inst, Krasnoyarsk 660036, Russia)
  • Flerov Igor (Russian Acad Sci, Siberian Div, LV Kirensky Phys Inst, Krasnoyarsk 660036, Russia; Siberian Fed Univ, Inst Engn Phys, Krasnoyarsk 660041, Russia)
  • Laptash Nataly (Russian Acad Sci, Far Eastern Div, Inst Chem, Vladivostok 690022, Russia)