| Автор | A A Bokov |
| Автор | V Y Shonov |
| Автор | I P Rayevsky |
| Автор | E S Gagarina |
| Автор | M F Kupriyanov |
| Дата выпуска | 1993-08-02 |
| dc.description | The possibility of varying the compositional long-range order parameter s and the influence of s on the ferroelectric properties of pure and Li-doped Pb(Yb<sub>0.5</sub>Nb<sub>0.5</sub>)O<sub>3</sub> ceramics have been studied. X-ray diffraction and dielectric measurements were used. A compositional order-disorder phase transition was discovered at 1120 degrees C (in doped ceramics). It was shown that in the course of material synthesis the compositionally ordered perovskite structure is formed at comparatively low temperatures (800 degrees C) and the s value may be reduced during sintering at higher temperatures. The pure ceramic remains ordered after sintering because the rate of s change in it is much lower than in the doped material. Low-temperature sintered doped ceramics are characterized by spatial non-homogeneities of s, causing the appearance of two (or more) anomalies in the temperature dependence of the permittivity. The T-s phase diagram has been investigated. Materials with a low s (s<s<sub>c</sub>) show a diffuse transition from high-temperature paraelectric phase to ferroelectric phase (at T<sub>C</sub>=115 degrees C when s = 0). For materials with a high s (s>s<sub>c</sub>) a paraelectric to antiferroelectric phase transition is observed. Thus there is a triple point at s=s<sub>c</sub>. The Curie temperature T<sub>C</sub> is quadratic in s and a minimum in the T<sub>C</sub>(s) curve is observed at the triple point, which is in agreement with the earlier theoretical treatment of Bokov et al. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Compositional ordering and phase transitions in Pb(Yb<sub>0.5</sub>Nb<sub>0.5</sub>)O<sub>3</sub> |
| Тип | paper |
| DOI | 10.1088/0953-8984/5/31/013 |
| Electronic ISSN | 1361-648X |
| Print ISSN | 0953-8984 |
| Журнал | Journal of Physics: Condensed Matter |
| Том | 5 |
| Первая страница | 5491 |
| Последняя страница | 5504 |
| Аффилиация | A A Bokov; Rostov State Univ., Russia |
| Аффилиация | V Y Shonov; Rostov State Univ., Russia |
| Аффилиация | I P Rayevsky; Rostov State Univ., Russia |
| Аффилиация | E S Gagarina; Rostov State Univ., Russia |
| Аффилиация | M F Kupriyanov; Rostov State Univ., Russia |
| Выпуск | 31 |
