Dielectric relaxation in non-polar nematic liquid crystal devices

We investigate the dielectric relaxation in non-polar nematic planar aligned liquid crystal samples by means of both dielectric spectroscopy and a transient current method. The dielectric functions, obtained by the impedance data, are modeled by the modified Havriliak-Negami method, which allows to determine spectra in terms of permittivity, conductivity and dielectric relaxation. Further information on the involved electric charge and the ion mobility is achieved by means of current measurements. The outcomes demonstrate that the effective relaxation times originate from ionic polarization and depend on the interfaces properties, pointing out the influence of the layered structure.