MOLECULAR ROTATIONAL POTENTIALS IN THE SC-STAR PHASE OF BINARY FERROELECTRIC LIQUID-CRYSTAL MIXTURES

The spontaneous polarization and tilt angle have been measured as a function of temperature and concentration in the Sc* phase of four binary ferroelectric liquid crystal mixtures. The substances have been chosen in a way that different situations could be studied, for example mixtures of a chiral substance (Ps non-zero) with a non-chiral one (Ps = 0) and mixtures of chiral compounds with the same sign ofPs as well as with opposite signs. The results have been interpreted by means of a molecular rotational model and potentials associated with the tilt as well as with the chirality have been determined as a function of concentration. © 1990 Taylor and Francis Ltd.