Theoretical studies of the influence of backflow on the dynamical behaviour of a Fredericks transition of a ferroelectric smectic C∗ liquid crystal in the bookshelf geometry

Abstract

The elastic-hydrodynamic theory for the ferroelectric smectic C∗ phase is reviewed and the governing equations for the dynamical behaviour of a surface stabilized ferroelectric liquid crystalline cell are written down, taking the possibility of macroscopic mass flow in the system into account. The influence of backflow effects on the dynamical cell behaviour and a control parameter, determining whether backflow effects will be of importance or not, is derived. It is shown that when backflow effects are pronounced, the response time of the switching can be considerably decreased. Also, the shape of the c-director and velocity profiles across the cell are shown to be strongly dependent on the presence of backflow.