Impedance spectroscopy investigation of electrophysical characteristics of the electrode-liquid crystal interface

The behavior of frequency dependences of the impedance of a capacitive measuring cell with a liquid crystal has been investigated in the frequency range from 10$^{-1}$ to 10$^5$ Hz. A method for determining electrophysical characteristics of the liquid crystal in the bulk and at the liquid crystal-metal electrode interface has been proposed and tested for liquid crystals of the alkyl cyanobiphenyl series, which are doped with ionic surfactants. The method is based on the use of an equivalent electrical circuit, which makes it possible to approximate the impedance spectra with the required accuracy, and also on the determination of the frequency at the singular point in the impedance spectra, at which the reactive component of the electric current flowing through the liquid-crystal cell is negligible compared to the active component.