Dielectric and phase transition studies on liquid crystal cholesteryl oleate [pure]

The liquid crystal cholesteryl oleate (ChO) has been studied through the measured electric permittivity (ϵ´) and loss (ϵ") over a vide range of temperature extending from its crystal phase to isotropic phase and at different spot frequencies in the range 1.25 to 200 MHz. The dipole moment, dielectric relaxation time and other related parameters have been evaluated and interpreted in terms of molecular structure in different mesophases A symmetric Cole-Cole distribution curve with an extrapolated high frequency limiting value of permittivity (ϵ_∞) represents the dielectric behaviour in its Ch and SmC phases. The phase transition of ChO has also been studied through the measured ϵ_s density and the refractive index. The results have been compared to that obtained from hot stage optical photomicrosdopy studies. The density data seems to be in closer agreement to that of photomicroscopy. Significant structure theory has also been applied.