Dependence of the SmC* layer reorientation dynamics on enantiomeric excess

The process of the in-plane reorientation of smectic layers under applicati on of asymmetric electric fields was investigated with respect to the enant iomeric excess. Measurements were carried out as a function of electric fie ld asymmetry ratio, electric field amplitude and temperature. The enantiome ric excess was varied by mixing chiral antipodes of a ferroelectric smectic C* liquid crystal. We observed the general dynamic behaviour previously re ported for a variation of external parameters: increasing layer reorientati on velocity with increasing field asymmetry and amplitude and strongly decr easing layer reorientation velocity for decreasing temperature in the SmC* phase. The smectic layer reorientation dynamics is found to be slowed down linearly by decreasing the enantiomeric excess. The rotation vanishes on ap proaching the racemic mixture. The layer reorientation process changes its direction as the racemic composition of enantiomers is crossed.