Influence of flexoelectricity above the nematic Freedericksz transition

Continuum theory is used to demonstrate that the presence of flexoelectricity significantly alters the response to an applied voltage of a homogeneous nematic liquid crystal cell above the ac Fræ#169;edericksz threshold voltage. In such a system there is a fitting degeneracy: we obtain very good fits between theory and experimental permittivity data using any value of the sum of flexoelectric coefficients, e11 + e33, between 0.0 C/m and 1.5×10-11 C/m. The corresponding values of the nematic bend elastic constant show an inverse parabolic relationship with e11 + e33, with K33 being reduced down to 90% of its value when flexoelectricity is neglected.