| Autor: |
C. Destrade, A. Bouchta, J. P. Parneix, H. T. Nguyen, F. Bibonne, G. Joly, N. Isaert |
| Rok vydání: |
1995 |
| Předmět: |
|
| Zdroj: |
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals. 263:27-35 |
| ISSN: |
1058-725X |
| Popis: |
The dielectric dispersion in the ferroelecric and antiferroelectric phases of a new liquid crystal (S)-4-(1-methylheptyloxycarbonyl)-phenyl 4-(4-dodecyloxybenzoyloxy)benzoate has been investigated in the frequency range from 10 Hz to 10 MHz. The behaviour of the soft mode in SmA and the Goldstone mode in SmC* have been determined. Two dielectric relaxations have been recognized in the antiferroelectric SmC*A phase : the first one between 5 kHz and 50 kHz and the second one, also observable in the ferrielectric SmC*FI phase, around 1 MHz. In SmC*FI, a drastic change in the behaviour of the low frequency response has been found depending on whether the sample was heated or cooled. A sign reversal of the helical pitch has been determined inside the SmC*FI phase, leading to low pitch values of opposite sign in SmC*A and SmC*. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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