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Updated: Jun 14, 2026

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Orientational order parameters in liquid crystals: a comparative study of x-ray diffraction and polarized Raman
Alberto Sanchez-Castillo1, Mikhail A Osipov, Frank Giesselmann
1Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
Abstract:
The orientational order parameters
and
in the nematic liquid crystal 4-pentyl-4'-cyanobipheny (5CB) have been determined by means of the two completely different techniques: polarized Raman spectroscopy and x-ray scattering. In particular, the values of
and
obtained using two different Raman methods, proposed by Jen [J. Chem. Phys 66, 4635 (1977)] and Jones [J. Mol. Struct. 708, 145 (2004)], respectively, are compared with the results of x-ray measurements. A good agreement between the experimental values of
and
and the results of the Humphries-James-Luckhurst mean field theory has been found whenever they were determined using either x-ray measurement or following the Jen method. In addition, a study of the influence of the intensity of the exiting laser source on the apparent values of the order parameters has been performed. Therefore, it was found that the discrepancies of the value of
determined following Jen and Jones could be determined by nonlinear effects.
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