SOME CONSIDERATIONS ON THE INFLUENCE OF THE FLEXOELECTRICITY ON THE CRITICAL THICKNESS OF A HYBRID ALIGNED NEMATIC CELL

We discuss the influence of flexoelectricity on the critical thickness of a hybrid aligned nematic liquid crystal cell, taking into account the surface-like volume elasticity and supposing that the anchoring energy is due only to the dispersion forces. We show that the critical thickness is independent of the flexoelectrical properties of the nematic liquid crystal, and that this conclusion is valid also in the case of generic anchoring energy (dispersion + steric interaction). Furthermore, the possibility of spontaneous Freedericksz transition is shown according to the importance of the elastic coefficient associated to the surface-like volume elasticity with respect to the splay elastic constant.