Phase transition and birefringence studies on some ferroelectric liquid crystals

Abstract

In the present studies the homologous series of hydroxy phenylamino methyl phenoxy benzoate liquid crystals (n = 8,9 and m = 6) are used. The temperature variation of density is measured. Using density data the phase variants in the compounds are identified. All the compounds exhibit first-order phase transitions. By Newton rings method the birefringence is measured directly in smectic and nematic phases. The advantages of the newton ring technique are presented over the conventional methods for the determination of orientational order parameter. The orientational order parameter attained by the newton rings scheme is equated through the literature data, the results are discussed.