DOI: 10.1140/epje/i2002-10127-8
Poling of liquid crystals in thin films
P.C. Schuddeboom, R. Meister, E. Cecchetto and B. JérômeDepartment of Chemical Engineering, University of Amsterdam Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands jerome@science.uva.nl
(Received 13 December 2002 and Received in final form 31 March 2003 / Published online: 21 May 2003)
Abstract
We examine the effect of a strong DC electric field on the
molecular orientational order and the nonlinear optical response of
liquid crystals in thin films. We compare the results of
second-harmonic generation measurements with the predictions of two
models, one assuming that the dipoles carried by the molecules have no
interactions (the isotropic model), and the other assuming that the
dipoles evolve in a Maier-Saupe orienting field responsible for the
liquid-crystalline order (the Maier-Saupe model). In both cases, we
take into account the effect of surfaces and confinement on the
behavior of the molecules. We find that the molecular dipoles behave
as predicted by the isotropic model, but that their reorientation is
correlated in such a way that the apparent dipole moment of the
reorienting units is one order of magnitude larger than the molecular
dipole moment.
61.30.Gd - Orientational order of liquid crystals; electric and magnetic field effects on order.
61.30.Hn - Surface phenomena: alignment, anchoring, anchoring transitions, surface-induced layering, surface-induced ordering, wetting, prewetting transitions, and wetting transitions .
42.70.Df - Liquid crystals.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2003
