Eur. Phys. J. B 6, 341-345 (1998)
https://doi.org/10.1007/s100510050559

Helically modulated electroclinical effects in twist grain boundary liquid crystals

¹ Centre de Recherche Paul Pascal - CNRS, avenue A. Schweitzer, 33600 Pessac, France
² Institut Non-Linéaire de Nice, Sophia-Antipolis, 1361 route des Lucioles, 06560 Valbonne, France

Received: 24 April 1998
Revised: 22 June 1998
Accepted: 31 July 1998
Published online: 15 December 1998

Abstract

We report the first observation of an electroclinical effect at the TGB_C–TGB_A transition induced by an external DC electric field applied perpendicular to the pitch direction. Upon increasing the field, the smectic layers rather than the director field tilt over relative to the helical axis, allowing to detect the effect by X-ray scattering from well aligned samples. The observations are qualitatively interpreted in the frame of a mean field phenomenological model of a helically modulated electroclinical effect.