Тип публикации: статья из журнала
Год издания: 2013
Идентификатор DOI: 10.1134/S1063783413040045
Аннотация: The temperature dependences of the heat capacity C-p(T) and thermal expansion coefficient alpha(T) of NaNbO3 ceramic samples have been investigated in the temperature range from 2 to 800 K. In addition to the anomalies associated with the known phase transitions at temperatures T-6 approximate to 265 K, T-5 approximate to 638 K, T-Показать полностью4 approximate to 760 K, and T-3 approximate to 793 K, anomalies in the behavior of C-p(T) and alpha(T) have been observed near T-5 '' approximate to 500 K and T-5' approximate to 600 K. It has been found that all the observed structural transformations, according to the values of the entropy change, are not related to the ordering of structural elements. It has been shown that, with an increase in the temperature, the unit cell volume during the phase transitions near 265, 515, 604, and 638 K decreases. The specific features of the transition to the phase R3c have been examined. Two possible scenarios of the sequence of phase transformations in the temperature range between T-5 and T-6 have been analyzed.
Журнал: PHYSICS OF THE SOLID STATE
Выпуск журнала: Vol. 55, Is. 4
Номера страниц: 821-828
ISSN журнала: 10637834
Место издания: NEW YORK
Издатель: MAIK NAUKA/INTERPERIODICA/SPRINGER