Тип публикации: статья из журнала
Год издания: 2014
Идентификатор DOI: 10.1080/01411594.2013.878026
Ключевые слова: phase transition, ferroelectric, order-disorder, statistical mechanics, Ferroelectric materials, Order disorder transitions, Phase transitions, Temperature, Electric polarization, Ferroelectric phase transition, Loss of stability, Low temperature phase, Mechanisms of formation, Ordered perovskite, Orientational phase transition, Statistical modeling, Positive ions
Аннотация: Based on the structural data on the phases of cryolite (ordered perovskite) K3WO3F3, we develop a statistical model, which allows to describe the sequence of phase transitions observed in this compound using a unified approach. According to the model, the crystal possesses two structural subsystems: the K cations located in the octПоказать полностьюahedral positions and the WO3F3 octahedra in positions alternating with K cations. In the symmetric (cubic) phase, each subsystem can be found in one of the eight states. At decreasing temperature, an orientational phase transition in the subsystem of octahedra occurs first, followed by a phase transition to the low-temperature phase, caused by the loss of stability with respect to the ordering in the K cation subsystem. We find that the electric polarization occurs as pseudoproper and discuss the mechanisms of formation of the phase states.
Журнал: PHASE TRANSITIONS
Выпуск журнала: Vol. 87, Is. 6
Номера страниц: 592-602
ISSN журнала: 01411594
Место издания: ABINGDON
Издатель: TAYLOR & FRANCIS LTD