Dielectric relaxation and anisotropy of nematic mixture E-24

The dielectric anisotropy and dispersion of the real and imaginary part of permittivity of commercially important nematic mixture E-24 were investigated in the frequency range from 1 kHz to 10 MHz and temperature range 287-328 K. The measurements in nematic phase indicate Debye-type dispersion with relaxation time of 1.07 μs at 313 K and activation energy 41.01 kcal/mol. The results have been explained by assuming the molecular rotation about the long molecular axis under a hindering nematic potential. The dielectric anisotropy Δε is positive and the mean dielectric permittivity falls with rising temperature. Δε is also used to determine the order parameter for varying temperature.