Electric field effects of dielectric and ferroelectric properties in chiral smectic liquid crystal dobambc

TLDR: In this article, the dc bias field dependence of high frequency dielectric constant from 1 MHz to 100 MHz was measured in the helicoidal smectic C phase of ferroelectric liquid crystal (+)DOBAMBC.

Abstract: Applied field dependence of static dielectric constant, and also dc bias field dependence of high frequency dielectric constant from 1 MHz to 100 MHz are measured in the helicoidal smectic C phase of ferroelectric liquid crystal (+)DOBAMBC. A very low characteristic threshold field, which may be thought as a coerceive field of Goldstone mode, E = 3.8 × 10−3 V/cm (at 82°C) was found in the static dielectric constant measurement by lock in amp and thermal noise method. The high frequency dielectric constant is temperature independent above from 10 MHz. A lucid ⊊ -E hysteresis loop by dc bias field E and its critical behaviour in 50 MHz region are observed.