Dielectric properties of chiral ferroelectric liquid crystalline compounds with three aromatic rings connected by ester groups

0509430 - FZÚ 2020 RIV CH eng J - Journal Article
Das, M.K. - Barman, B. - Das, B. - Hamplová, Věra - Bubnov, Alexej M.
Dielectric properties of chiral ferroelectric liquid crystalline compounds with three aromatic rings connected by ester groups.
Crystals. Roč. 9, č. 9 (2019), s. 1-13. ISSN 2073-4352. E-ISSN 2073-4352
R&D Projects: GA ČR GA19-03564S
Institutional support: RVO:68378271
Keywords : ferroelectric liquid crystals * lactic acid derivative * dielectric spectroscopy * dielectric strength * relaxation time * structure property correlations
OECD category: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics
Impact factor: 2.404, year: 2019
Method of publishing: Open access

The tilted ferroelectric SmC* phase of three structurally different series of lactic acid derivatives with ester linkage groups in the molecular core has been studied by broad band dielectric spectroscopy. The dielectric spectra strongly depend both on the temperature as well as the specific molecular structure of the self-assembling compounds possessing the ferroelectric polar order. In the SmC* phase, the real and imaginary parts of the complex permittivity increase up to certain temperature near the SmC*-N*/SmA* transition and then decreases with increasing temperature, perhaps due to the disruption of the molecular domains at the onset of the SmA*/N* phase transition. The dielectric strength is also influenced by the difference in the alkyl chain length and type of linkage group of the constituent molecules. The relaxation time and the relaxation frequency are found to vary with the molecular structure of the studied ferroelectric compounds.

Permanent Link: http://hdl.handle.net/11104/0300180