Dielectric properties of dipolar substances

From an investigation of structure it is shown that there exists a large group of dipolar organic solids whose dipoles have two equilibrium positions with opposite dipole direction. To calculate the dielectric properties Onsager’s theory has been extended and developed into a systematic approximation which converges above a critical temperature. To derive the local field acting on a dipole we have replaced the surroundings by a continuum whose dynamic dielectric properties we have taken into account. As a result we find larger dielectric constants and smaller dielectric losses than in Onsager’s theory. We have also shown that liquids with high viscosity behave similarly to solids, while for liquids with low viscosity there are no such deviations from Onsager’s theory.