Jpn. J. Appl. Phys. 44 (2005) pp. 7532-7538  |Previous Article| |Next Article|  |Table of Contents|
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Microscopic Description of the Dielectric Experiment of Some Liquid Crystals^*

Wojciech Otowski, Dietrich Demus¹ and Agnieszka Biernat

(Received September 16, 2004; accepted May 19, 2005; published October 11, 2005)

Dielectric properties measure the collective response of a charge-free system to an applied electric field, and are a probe of molecular polarizability, dipole moment and the internal field in the anisotropic media. Interactions between dipoles cannot be discounted in the molecular interpretation of the dielectric properties of liquid crystals. So, the theories for these properties are more complicated than for magnetic or optical properties. This paper presents comparison of the predictions of the Nordio–Rigatti–Segre theory with the results of the broadband dielectric studies of the dielectric relaxation processes of a few macroscopically oriented liquid crystals. Using the quantum chemical program MOPAC/7, with the AM1 Hamiltonian a few essential values have to be calculated in advance. Moreover a new procedure for the calculation of the order parameter has been proposed.

URL: http://jjap.jsap.jp/link?JJAP/44/7532/
DOI: 10.1143/JJAP.44.7532
KEYWORDS:dielectric spectroscopy, Nordio–Rigatti–Segre theory, molecular processes

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