Phason and amplitudon relaxation processes of a low pitch and large spontaneous polarization ferroelectric liquid crystal mixture

Abstract

Dielectric strength(Δε), relaxation frequency(frg), Cole-Cole distribution parameter (h) and dc conductivity (σdc) for phason fluctuations in SmC phase and amplitudon fluctuations in SmA* phase have been determined for a 15μm thick planar oriented ferroelectric liquid crystal mixture FLC#252 of high spontaneous polarization and low pitch (z=0.3-0.5μm). From the dielectric strength and relaxation frequency of the Goldstone mode, phason rotational viscosity (γφ) and elastic constant (Kφ) have been calculated. Away from the transition temperature (TC*A*=51.4°C), phason relaxation frequencies and rotational viscosities obey the Arrhenius behaviour. The soft mode relaxation frequencies in SmA* phase (frs) do not follow the Arrhenius nature, whereas the soft mode rotational viscosities (γθ) obey it. For the soft mode in SmA* phase it is observed that dielectric strength (Δεs), dielectric loss (ε(max) and (r-1) (r is the ratio of the static dielectric constant ε(O) to the high frequency limiting dielectric constant ε(∝)) follow the Curie-Weiss law.