Temperature dependence of the order parameters (spontaneous polarisation and the tilt angle) at various concentrations for a mixture of SCE9+SCE10

Abstract

The smectic A- smectic C* (AC*) transition in a binary mixture of SCE9+SCE10 is studied at various concentrations of SCE9 near (x c = 0.12) and above x c (tricritical concentration). The temperature dependences of the spontaneous polarisation and the tilt angle (order parameters) are calculated using our mean field model with the bilinear and biquadratic couplings between these two order parameters. The expressions derived from the mean field model are fitted to the experimental data from the literature and the coefficients given in the free energy are determined. It is demonstrated that our mean field model explains the observed mean field to tricritical behaviour in SCE9+SCE10.