Correlated reorientations in NH_4Al(SO_4)_2 12H_2O single crystals
- Single crystals of aluminium ammonium alum NH_4AI(SO_4)_2 12H_20 were investigated using dielectric spectroscopy in the frequency range 1 kHz to 1 GHz. On approaching the ferroelectric transition at 58 K from above, a monodispersive polar mode is observed to slow down. The relaxation data can be described in terms of a pure Arrhenius law. The analysis of the dielectric loss reveals that in the paraelectric phase the static susceptibility cannot be described by a single Curie-Weiss law. The thermal variations of the Curie constant indicate that the dipolar correlations of the ammonium ions increase as the temperature is lowered.
| Author: | R. Böhmer, Peter LunkenheimerORCiDGND, J. K. Vij, I. Svare |
|---|---|
| URN: | urn:nbn:de:bvb:384-opus4-8902 |
| Frontdoor URL | https://opus.bibliothek.uni-augsburg.de/opus4/1035 |
| Parent Title (English): | Journal of Physics: Condensed Matter |
| Type: | Article |
| Language: | English |
| Year of first Publication: | 1990 |
| Publishing Institution: | Universität Augsburg |
| Release Date: | 2008/06/20 |
| Tag: | single crystals; dielectric spectroscopy; ferroelectric transition; Curie constant; relaxation |
| GND-Keyword: | Impedanzspektroskopie; Ferromagnetische Phasenumwandlung; Curie-Temperatur; Relaxation |
| Volume: | 2 |
| Issue: | 24 |
| First Page: | 5433 |
| Last Page: | 5438 |
| DOI: | https://doi.org/10.1088/0953-8984/2/24/014 |
| Institutes: | Mathematisch-Naturwissenschaftlich-Technische Fakultät |
| Mathematisch-Naturwissenschaftlich-Technische Fakultät / Institut für Physik | |
| Mathematisch-Naturwissenschaftlich-Technische Fakultät / Institut für Physik / Lehrstuhl für Experimentalphysik V | |
| Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
