Effect of pressure on the spontaneous polarisation, the critical unwinding field and the transverse dielectric constant in ferroelectric liquid crystals

Abstract

Because of their remarkable electro-optical effects ferroelectric liquid crystals have gained increasing interest during the last few years. Although extensive studies of different physical properties have been carried out at room pressure, few reports are available on the effect of pressure on these properties. We report here the effect of high pressure on spontaneous polarisation Ps the critical unwinding field Ec - defined as the magnitude of the external field necessary to unwind the helix - and the transverse static dielectric constant €ι. The stildies show that with increasing pressure both Ps and €ι decrease while Ec increases.