Тип публикации: статья из журнала
Год издания: 2008
Идентификатор DOI: 10.1134/S1063783408030219
Аннотация: The temperature dependences of the heat capacity, the unit cell parameter, and the permittivity for the (NH4)(3)MoO3F3 cryolite (space group Fm (3) over barm) are investigated. It is revealed that the compound undergoes ferroelectric and ferroelastic structural phase transitions at temperatures of 297 and 205 K, respectively. The mПоказать полностьюechanism of structural distortions is discussed in terms of the entropy parameters, pressure-temperature phase diagrams, and electron density maps for critical atoms. An analysis is made of the influence of the cation size and shape on the phase transitions in oxyfluorides of the general formula A(2)A'MO3F3 (A,A' = NH4, K; M = Mo, W).
Журнал: PHYSICS OF THE SOLID STATE
Выпуск журнала: Vol. 50, Is. 3
Номера страниц: 515-524
ISSN журнала: 10637834
Место издания: NEW YORK
Издатель: MAIK NAUKA/INTERPERIODICA/SPRINGER