Direction of the Polarization P on the Bounding Surfaces of Chiral Smectic C Samples

Abstract

A ferroelectric liquid crystal should have an intrinsic tendency to direct its local polarization vector P towards or away form a bounding surface. This, in principle, leads to an undesired splay inhomogeneity in ferroelectric optic cells. The direction has previously been determined in one case, by Glogarova and Pavel, to be away from the surface. We have found, for two different materials at the same surface, that the tendency i s opposite in the two cases. Thereby the possibility exists to achieve an essentially non-polar interaction by mixing, in order to avoid the splay. If the sign of P is known for the material, an optical observation is sufficient for the surface polarity determination. This means that there is even no need for an electric field, which simplifies the method.