Dielectric Absorption in Polar Media and the Local Field

The phenomena of dielectric dispersion and absorption in polar liquids subject to applied high frequency electrical fields are discussed on the basis of a modified Onsager theory for the local field. The results of this theory agree quite as well with experiment as do those from Debye's application of the hypothesis of hindered rotation with which the present work is compared. The application of the modified theory to the static case is also considered. A law of corresponding states is found to exist for the alcohols and an empirical equation proposed by Van Arkel and Snoek for ``normal'' polar liquids is shown to have an explanation in terms of the local field. The desirability of more complete measurements of dielectric constants and absorption as a function of temperature and frequency is stressed.