Abstract
Dielectric relaxation phenomena have been investigated for the antiferroelectric liquid-crystal compound (S)-4-(1-methylheptyloxycarbonyl)phenyl-4-(6-heptanoyloxyhex-1-oxy)biphenylate, exhibiting a paraelectric SmA* phase, a ferroelectric SmC* phase, and a wide-temperature-range (∼54–86.0°C) antiferroelectric phase. Dielectric investigations under planar molecular anchoring have been carried out in the frequency range 0.1 Hz to 10 MHz. The paraelectric SmA* phase shows soft mode relaxation related to amplitudons. Its relaxation frequency is highly temperature dependent, and decreases with decrease in temperature. The dielectric strength obeys Curie–Weiss law. The ferroelectric SmC* phase shows a Goldstone mode of relaxation related to the phasons. The relaxation frequency of this mode lies at ∼3.6 kHz, and is almost invariant with temperature. The dielectric strength of the Goldstone mode slowly increases with decrease in temperature. Two characteristic absorption peaks are seen in the phase: the higher-frequency peak corresponds to antiphase fluctuation of the azimuthal angle of directors in the anti-tilted molecular pairs, whereas the lower-frequency peak corresponds to in-phase fluctuation of the azimuthal angle of directors in the anti-tilted molecular pairs.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
