Studies On Surface Polarization, Flexoelectric Polarization And Bistable State Of NLC Cell

We study the influences of the surface polarization and the flexoelectric polarization on Freedericksz transition of non-symmetric weak anchoring NLC cell. We get rigorously Gibbs free energy of the system under electrical field, which involve the Frank free energy, the dielectric free energy, the flexoelectric free energy, the Surface polarization free energy and the anchoring free energy. The differential equation and boundary condition of the director angleθare obtained by applying the proper mathematical method. According to the equation and the boundary conditions thatθsatisfies, we get the specific formula of the uniform twisted free state, the disturbed free state and the saturation free state. The results show that except the usual second-order transition, the first-order Freedericksz transition can also emerge under the certain conditions and there is bistable state. The conditions for the existence of the first-order Freedericksz transition are obtained.