Theoretical Prediction of Sign Reversal of the Spontaneous Polarization in the Ferroelectric, Chiral Smectic C* Phase

Abstract

With a generalized Landau expansion of the free-energy density as a basis, we have earlier presented a coherent model, with which we can calculate the temperature dependence of the tilt, polarization, pitch, dielectric susceptibility and heat capacity of the ferroelectric, SmC phase in agreement with experiment (work submitted- to Mol. Cryst. Liq. Cryst.). A brief review of this model is given and it is shown explicitely, that under certain circumstances the model predicts a sign reversal of the spontaneous polarization of the system. The nature of this transition is discussed and a simple expression of the tilt angle at the transition is derived.