Measurement of dielectric response of 1MC1EPOPB and 1BC1EPOPB ferroelectric liquid crystals

Dielectric measurements have been carried out using an impedance analyzer for two ferroelectric liquid crystals R-4´ (1-methoxycarbonyl-1-ethoxy) phenyl 4-(4-octyloxy phenyl) benzoate (1MC1EPOPB) and R-4´ (1-butoxycarbonyl-1-ethoxy) phenyl 4-(4-octyloxy phenyl) benzoate (1BC1EPOPB). The two types have large spontaneous polarization, +1700 μC/m² for 1MC1EPOPB and +2400 μC/m² for 1BC1EPOPB. The permittivity and dielectric loss have been measured at different temperatures in the range 343.0 K to 383.0 K for 1MC1EPOPB and 318.0 K to 353.0 K for 1BC1EPOPB in the frequency range 2 Hz to 2 MHz. Both of the ferroelectric liquid crystals, 1MC1EPOPB and 1BC1EPOPB show a new phase smectic X along with smectic C* and smectic A phases. The work reported in this paper is new and is very useful in understanding their application in switching devices.