| Автор | J Zaleski |
| Автор | Cz Pawlaczyk |
| Автор | R Jakubas |
| Автор | H-G Unruh |
| Дата выпуска | 2000-08-21 |
| dc.description | The crystal structure of DMABA has been determined at 293 and 180 K. It crystallizes in the monoclinic P2<sub>1</sub>/c space group. The structure was refined to R<sub>1</sub> = 0.0466 for 1269 independent reflections at 293 K and R<sub>1</sub> = 0.038 for 1728 reflections at 180 K. DMABA is isomorphous with the chlorine analogue, DMACA. Its anionic sublattice forms corrugated two-dimensional layers in the bc plane. There are two crystallographically independent, disordered dimethylammonium cations in the crystal structure. One of them occupies cavities inside the polyanionic layers; the other is located between the layers. The temperature dependence of lattice parameters has been determined between 100 and 290 K. The presence of the ferro-paraelectric phase transition at 164 K has been confirmed. The complex dielectric permittivity of DMABA single crystals in the frequency range 100 Hz-10 GHz between 10 K and 300 K has been measured. The dynamic dielectric behaviour of DMABA is found to be determined by the properties of two independent relaxators: a low frequency one (~1 MHz at T<sub>c</sub>) with a critical slowing down of its dynamics and a high frequency one (~5 GHz), which is thermally activated and contributes to the electric permittivity at least from about 80 K. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Structure and dynamic dielectric behaviour of ferroelectric [NH<sub>2</sub>(CH<sub>3</sub>)<sub>2</sub>]<sub>3</sub>Sb<sub>2</sub>Br<sub>9</sub> (DMABA) |
| Тип | paper |
| DOI | 10.1088/0953-8984/12/33/316 |
| Electronic ISSN | 1361-648X |
| Print ISSN | 0953-8984 |
| Журнал | Journal of Physics: Condensed Matter |
| Том | 12 |
| Первая страница | 7509 |
| Последняя страница | 7521 |
| Выпуск | 33 |
