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Series

Kent State University

1991

Light Scattering

Articles 1 - 2 of 2

Full-Text Articles in Physics

Critical-Behavior At The Nematic To Smectic-A Transition In A Nonpolar Liquid-Crystal With Wide Nematic Range, Li Chen, J. D. Brock, J. Huang, Satyendra Kumar Oct 1991

Critical-Behavior At The Nematic To Smectic-A Transition In A Nonpolar Liquid-Crystal With Wide Nematic Range, Li Chen, J. D. Brock, J. Huang, Satyendra Kumar

Physics Publications

High-resolution x-ray scattering experiments to study the critical smectic-A fluctuations in the nematic phase have been performed on a mixture of two nonpolar, two-benzene-ring compounds. The ratio T(NA)/T(NI) (= 0.885) for this mixture is much smaller than for previously studied similar materials. The smectic correlation lengths parallel and perpendicular to the smectic-layer normal are found to diverge anisotropically with characteristic exponents-nu parallel-to = 0.75 +/- 0.03, nu perpendicular-to = 0.65 +/- 0.03, and the susceptibility with gamma = 1.24 +/- 0.05.


Nematic-Isotropic Phase-Transition In A Liquid-Crystal Droplet, S. Kralj, S. Zumer, David W. Allender Mar 1991

Nematic-Isotropic Phase-Transition In A Liquid-Crystal Droplet, S. Kralj, S. Zumer, David W. Allender

Physics Publications

Possible phases in a nematic liquid crystal confined to a spherical submicrometer droplet embedded in a solid polymer are analyzed in terms of a Landau-de Gennes theory. For a droplet with a radial structure we show that the strength of the nematic-polymer interfacial interaction affects the nematic-paranematic (partially ordered isotropic phase) phase transition and may in addition induce a boundary-layer nematic phase. This boundary layer phase exists only in a narrow (approximately 0.1 K) temperature interval above the nematic phase for a restricted range of interfacial interactions. Also in the radial structure the degree of ordering is suppressed close ...