Eur. Phys. J. E 4, 293-297

Simple Landau model of the smectic-A-isotropic phase transition

P.K. Mukherjee^{1, 2}, H. Pleiner³ and H.R. Brand<sup>1

1</sup>  Theoretische Physik III, Universität Bayreuth, D-95540 Bayreuth, Germany
²  Department of Physics, Haldia Govt. College, P.O.-Debhog, Dist.-Midnapur, Pin-721657, India
³  Max-Planck-Institut für Polymerforschung, 55021 Mainz, Germany

brand@uni-bayreuth.de

(Received 27 June 2000)

Abstract
A simple Landau-type free energy function is presented to describe the smectic-A-isotropic phase transition. Varying the coupling between orientational and positional order parameters, a smectic-A-isotropic or a nematic-isotropic phase transition occurs. Within this model the smectic-A-isotropic phase transition is found to be always more strongly first order than the nematic-isotropic phase transition. The theoretical results are found to be in good agreement with all published experimental results.

PACS
64.70.Md - Transitions in liquid crystals.
05.70.Fh - Phase transitions: general studies.
61.30.-v - Liquid crystals.


© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2001