Influence of dc voltage on the dielectric properties of nematics.

We report on precise impedance measurements, with the aim of exploring the influence of a dc bias voltage on the dielectric permittivity and electrical conductivity of liquid crystals and on their anisotropies. We prove that the dielectric permittivity is not affected by a dc bias; however, the electrical conductivity suffers a substantial reduction upon increasing the superposed do voltage. Moreover, we show that the relative conductivity anisotropy also diminishes at increasing do bias