Anomalous Dielectric Behaviour in Biphenyl Ester Series of Ferroelectric Liquid Crystals

Abstract
In ferroelectric liquid crystals of biphenyl ester series with alkylcarbonyloxy (C n H2n+1COO) chain length n longer than 9 exhibit anomalous dielectric behaviour. The spontaneous polarization becomes 0, even in the chiral smectic-C phase, at around 30°C at which the reversal of the sign of the tilt angle is observed, indicating a change of the sign of the spontaneous polarization. The origin of this anomalous behaviour is also discussed in terms of molecular interactions.