Temperature Sensitive Helical Pitches and Wall Anchoring Effects in Homogeneous Monodomains of Ferroelectric Sm C* Liquid Crystals, nOBAMBC (n=6-10)
- 1 February 1982
- journal article
- Published by IOP Publishing in Japanese Journal of Applied Physics
- Vol. 21 (2R)
- https://doi.org/10.1143/jjap.21.224
Abstract
2-methylbutyl p-(p-n-alkoxybenzylidencamino) cinnamates were synthesized and their helical pitches in the Sm C* phase were measured by optical microscopic and/or diffraction methods. After the phase transition from Sm A to Sm C*, the pitches increase steeply within 0.5°C, attain relatively broad maxima, and then gradually decrease in all the nOBAMBC investigated, except for HpOBAMBC (n=7) whose pitch shows some anomalies at low temperatures. The “odd-even effect” is clearly observed in the dependence of the maximum pitch on the alkoxy chain length. The dependence of the helical pitch on cell thickness has also been studied. During the steep increase, the wall anchoring effect is not observed when the cell is at least thicker than 100 µm; at lower temperatures, however, the pitch depends on the thickness even when the cell is as thick as 200 µm or more. Finally, the observed temperature variation of the pitch is compared with the Landau-type phenomenological theories so far proposed.Keywords
This publication has 12 references indexed in Scilit:
- Causes for the Appearance of Fringes in Cholesterics, Williams Domains and Chiral Smectic C Liquid CrystalsJapanese Journal of Applied Physics, 1981
- Preparation of Monodomain Cells of Ferroelectric Liquid Crystals and Their Evaluation with an Optical MicroscopeJapanese Journal of Applied Physics, 1981
- Temperature Variation of Helical Pitches in Chiral Smectic C Liquid Crystals as Observed with an Optical MicroscopeJapanese Journal of Applied Physics, 1980
- Dynamics of helicoidal ferroelectric smectic-liquid crystalsPhysical Review A, 1978
- Birefringence in the Sm A Phase and the Disappearance of Helicoidal Structure in the Sm C*Phase Caused by an Electric Field in DOBAMBCJapanese Journal of Applied Physics, 1978
- Thermodynamic states and symmetry of liquid crystalsSoviet Physics Uspekhi, 1978
- Piezoeffects and ferroelectric phenomena in smectic liquid crystalsFerroelectrics, 1978
- Phenomenological theory of the polarized helicoidal smecticCphasePhysical Review A, 1977
- Ferroelectric Liquid Crystals; A ReviewMolecular Crystals and Liquid Crystals, 1977
- Structure of the liquid crystalline state of cholesterol derivativesJournal of the American Chemical Society, 1968