Dependence of spontaneous polarization, rotational viscosity and helical pitch of smectic c* compounds on the enantiomeric excess

Abstract

We report on investigations of three distinct pure S_C* compounds for which we measured the dependence of the spontaneous polarization, the rotational viscosity, and the S_C*-pitch on enantiomeric excess. The quantities under consideration partly exhibit non-linear behaviour. A simple statistical model is proposed that accounts for both linear and non-linear dopant concentation dependencies of the spontaneous polarization. The rotational viscosity with respect to the ĉ-director increases with increasing spontaneous polarization. The inverse pitch, z⁻¹, exhibits a strongly non-linear behaviour for small concentrations, however, we do not observe a sharp threshold concentration below which no helix exists. Some practical consequences of our findings are discussed.