Journal ArticleDOI
Transient Electro-Optic Kerr Effect in Liquid Crystalline Isothiocyanates
TLDR
In this paper, the D.C. Kerr response and the pre-transitional behavior of two liquid crystalline isothiocyanates 4-(4 ′ -n-pentyl phenyl)-phenyl isothIocyanate (5NCS) and 4-( 4 ′ −n-heptylphenyl-phenyl)-isothIOCyanate(7NCS), at temperatures above the smectic-isotropic transition temperatures were investigated.Abstract:
Measurements are reported for the first time on the D.C. Kerr response and the pre-transitional behaviour of two liquid crystalline isothiocyanates 4-(4 ′ -n-pentyl phenyl)-phenyl isothiocyanate (5NCS) and 4-(4 ′ -n-heptyl phenyl)-phenyl isothiocyanate (7NCS) at temperatures above the smectic-isotropic transition temperatures. The Kerr law has been verified and the real part of the third order nonlinear susceptibilities (χ (3) ) above the smectic-isotropic transition are determined for the two liquid crystalline isothiocyanates from the electro-optic Kerr effect (EOKE) experiments. The variation of susceptibility with temperature has also been studied. The results have been compared with the cyanobiphenyls which have been widely studied and are known for their giant optical non-linearities.read more
Citations
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Journal ArticleDOI
Isotropic to smectic-A phase transition: A review
TL;DR: In this article, the authors present an attempt towards a unified picture of the direct transition from the isotropic to smectic-A phase, including structure and nature revealed by experiments, molecular models and Landau-de Gennes theory.
Journal ArticleDOI
New divergent dynamics in the isotropic to nematic phase transition of liquid crystals measured with 2D IR vibrational echo spectroscopy
TL;DR: The isotropic-nematic phase transition in liquid crystals is described in the context of the slowing of orientational relaxation associated with divergent growth of the orientational correlation length, and the correlation length of the density fluctuations is diverging with the same temperature dependence as the pseudonematic domain correlation length.
Journal ArticleDOI
Large Electro-Optic Kerr Effect in Ionic Liquid Crystals: Connecting Features of Liquid Crystals and Polyelectrolytes.
M. Christian Schlick,Nadia Kapernaum,Manuel M. Neidhardt,Tobias Wöhrle,Yannick Stöckl,Sabine Laschat,Frank Giesselmann +6 more
TL;DR: It is shown that maximum Kerr constants in the order of several 10-11 m V-2 make ionic liquid crystals attractive as new class of functional materials in low-speed Kerr effect applications.
Journal ArticleDOI
Critical Slowing of Density Fluctuations Approaching the Isotropic-Nematic Transition in Liquid Crystals: 2D IR Measurements and Mode Coupling Theory.
TL;DR: A remarkable change in coupling occurs at ∼5 K above TNI, precisely where the rate of spectral diffusion in 5CB was observed to deviate from that of a similar nonmesogenic liquid.
Journal ArticleDOI
Length scales and structural dynamics in nematogen pseudonematic domains measured with 2D IR vibrational echoes and optical Kerr effect experiments.
TL;DR: The results demonstrate that the presence of local orientational order at temperatures well above TNI does not affect the spectral diffusion (structural evolution) within pseudonematic domains when the correlation lengths are short, and density fluctuations are likely the source of spectral diffusion at temperatures at least 5 Kabove TNI.
References
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Journal ArticleDOI
New determination method of electro‐optic constants and relevant nonlinear susceptibilities and its application to doped polymer
Hisao Uchiki,Takayoshi Kobayashi +1 more
TL;DR: In this article, a new method was proposed for the determination of the electrooptic constants and relevant nonlinear susceptibilities of polycarbonate films doped with 4−diethylamino−4'−nitrostilbene.
Journal ArticleDOI
Isothiocyanates and their Mixtures with A Broad Range of Nematic Phase
TL;DR: In this paper, the outstanding feature of liquid crystalline isothiocyanates is the possibility to make mixtures with a wide range of nematic phase low viscosity and weak temperature dependence of viscosities.
Journal ArticleDOI
Kerr-effect investigations in a nematic liquid crystal.
John Philip,T. A. Prasada Rao +1 more
TL;DR: The dc Kerr constant and the pretransitional temperature of a polar nematic liquid crystal 4-(trans-4'-4'-n-pentylcyclohexy)-benzonitrile (PCH-5).
Journal ArticleDOI
The optical and electrical Kerr effect in 4-n-pentyl-4′-cyanobiphenyl
Harry J. Coles,B. R. Jennings +1 more
TL;DR: In this article, the permanent dipole moment and optical polarizability of 4n-pentyl-4′-cyanobiphenyl (5CB) were determined by using the pulsed method and it was shown that Δn and τ are proportional to (T - T*)-1.
Journal ArticleDOI
Third‐order nonlinear optical properties of poly(diphenyl amine) and poly(4‐amino biphenyl), novel processible conducting polymers
TL;DR: In this paper, the authors used degenerate four-wave mixing measurements in solution at 1.064 μm for partially doped states of the soluble, stable, reprocessible conducting polymers poly(4-amino biphenyl) [P(4ABP)] and poly(diphenyl amine) [DPA] whose synthesis and properties were reported earlier.
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