Induced twisted-grain-boundary phases in the binary mixtures of a cholesteric and a nematic compound |
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| Authors: | R Dhar AK Srivastava VK Agrawal |
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| Institution: | 1. Physics Department , Ewing Christian College , Allahabad-211 003, India;2. Physics Department , Allahabad University , Allahabad-211 002, India |
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| Abstract: | Thermodynamical, optical-texture and dielectric studies have been performed to study the phase diagram of the binary system of 5-cholesten-3β-ol-octanoate and 4-n-nonyloxybenzoic acid. It is observed that low concentrations of 5-cholesten-3β-ol-octanoate (2–30?mol?%) in 4-n-nonyloxybenzoic acid induce a mean-field phase diagram derived by Renn within the framework of the chiral Chen–Lubenski model. Various optical textures of the twisted-grain-boundary (TGB) phases under different conditions of molecular anchoring have been observed. Weak transitions related to the TGB phases have been detected by temperature dependent dielectric spectroscopy. |
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| Keywords: | Binary mixture TGB phases Chiral Chen–Lubenski model Dielectric permittivity |
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