Dielectric Loss in the Liquid Crystal p-Azoxyanisole

The real and imaginary parts of the complex dielectric constant of the normal liquid phase of p-azoxyanisole were measured at a temperature of 140°C for a frequency range from 900 Mc to 24 kMc. A plot of the complex dielectric constant in the complex plane satisfies the requirements for a Cole—Cole representation reasonably well. The temperature dependence of the dielectric loss at a frequency of 6 kMc shows an absorption maximum in the neighborhood of the clearing point (135°C) for both the anisotropic and normal liquid phases. Measurements of the dielectric loss at frequencies 500 and 900 Mc indicate an increase in the dielectric loss as the sample changes from the anisotropic to the normal liquid phase. This change could not be established for measurements at other frequencies reported in this paper.