Electrooptic and dielectric properties of new antiferroelectric liquid crystal mixtures

Abstract

Two new antiferroelectric liquid crystal mixtures based on optically active hydroxyesters have been studied with respect to their electro-optic and dielectric behavior. The mixtures exhibit only a SmA* phase above SmC_a* and show a stable antiferroelectric order over a broad temperature range (≈100°C). Electro-optic as well as dielectric studies suggest that the SmC_a*-SmA* transition is second order. In thin cells signs of a surface-induced SmC* phase has also been observed. We present the relevant characteristics for three different electro-optic modes which could be exploited in these materials, including the very fast linear mode for sub-threshold voltages.

Keywords:

• ferro- and antiferroelectric liquid crystals
• electro-optic switching
• dielectric spectroscopy
• surface-induced phases