Measurement of spontaneous polarization in ferroelectric smectic liquid crystals

Abstract

This paper presents measurements of spontaneous polarization made on two ester-bridged materials (SCE1 and CE8). The two materials are chosen to be representative of long pitch (SCE1) and short pitch (CE8) materials. The measurements were made by two different methods, Diamant bridge and field reversal; these methods are compared and the results shown to be in good agreement. The variation in results between different samples of these materials is discussed and the results compared (where possible) with the work of other authors. Special attention is paid to the variation which occurs between the published spontaneous polarization measurements of different authors. The reasons for this variation are examined and variation in sample alignment and the determination of the transition temperature by different authors are shown to be major causes.