| Автор | Alessandra Geddo Lehmann |
| Автор | Philippe Sciau |
| Дата выпуска | 1999-02-08 |
| dc.description | The ferroelastic symmetry changes of the lead-based complex perovskite PbFeY<sub>0.5</sub>Ta<sub>0.5</sub>O<sub>3</sub> are investigated by means of single crystal x-ray diffraction and observations in polarized light microscopy at different temperatures. The position of the 400 and 222 cubic reflections is followed between 80 K and 300 K. Results indicate the presence of two structural transitions at about 270 K and 220 K. Such temperatures define the stability range of three different phases. The high-temperature phase (T > 270 K) is the optically anomalous paraelectric prototype, the optical symmetry of which is uniaxial (tetragonal) in spite of the diffractometric (pseudo)cubic symmetry. The intermediate derived phase (270 K > T > 220 K) is tetragonal. This tetragonal phase coexists with a monoclinic one for 220 K > T > 200 K. Below 200 K only the monoclinic phase is stable. The (pseudo)cubic-to-tetragonal transition seems to be of the second order. The tetragonal-to-monoclinic one is of the first order. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Ferroelastic symmetry changes in the perovskite PbFeY<sub>0.5</sub>Ta<sub>0.5</sub>O<sub>3</sub> |
| Тип | paper |
| DOI | 10.1088/0953-8984/11/5/011 |
| Electronic ISSN | 1361-648X |
| Print ISSN | 0953-8984 |
| Журнал | Journal of Physics: Condensed Matter |
| Том | 11 |
| Первая страница | 1235 |
| Последняя страница | 1245 |
| Выпуск | 5 |
