Clark–Lagerwall effect in the small particles—Ferroelectric liquid crystal system

The smectic C* based on a three-component mixture of liquid crystals (LC) with not mesogene chiral additive and showing ferroelectric properties has been developed. The physical parameters which are responsible for electrooptical effects are defined. The Clark–Lagerwall effect both in the pure smectic C* and with the additive of small particles of the centrosymmetric substance Al2O3 and the ferroelectric SrTiO3 is investigated. It has been shown that time characteristics of a cell with LC-Al2O3 are a little bit worsened in comparison with a cell with pure LC. It is caused by increase of the rotational viscosity of the ferroelectric liquid crystal with addition of small particles Al2O3. Time characteristics of the Clark–Lagerwall effect in the LC-SrTiO3 cell essentially surpass time characteristics of the cell with pure LC because the transition from the deformed UP-state to the DOWN-state demands overcoming much lower energy than the transition from the pure UP-condition to the DOWN-state.