Тип публикации: статья из журнала
Год издания: 2020
Идентификатор DOI: 10.1134/S1063783420070057
Ключевые слова: birefringence, oxyfluorides, phase transitions, pressure susceptibility, specific heat, thermal expansion
Аннотация: Abstract: The (NH4)3VOF5 crystals have been synthesized and their homogeneity and single-phase structure has been established by the X-ray diffraction, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy studies. The investigations of the temperature dependences of specific heat, entropy, strain, and pressure susceПоказать полностьюptibility show the occurrence of three phase transitions caused by the structural transformations in the (NH4)3VOF5 crystals. The T–p phase diagram shows the temperature limits of stability of the crystalline phases implemented in (NH4)3VOF5. The optical and dielectric studies disclose the ferroelastic nature of the phase transitions. An analysis of the experimental data together with the data on the isostructural (NH4)3VO2F4 crystal makes it possible to distinguish the physical properties of oxyfluorides containing vanadium of different valences (IV and V). © 2020, Pleiades Publishing, Ltd.
Журнал: Physics of the Solid State
Выпуск журнала: Vol. 62, Is. 7
Номера страниц: 1271-1279
ISSN журнала: 10637834