Evaluation of Susceptibility Functions

Simple algebra is sufficient to show that all the commonly accepted, empirical susceptibility relationships exhibit power laws as functions of frequency, in the limits of both low and high frequencies. The exponents of these power law relationships are presented and it is shown that simple relationships exist between them. It is established that the Debye relationship is unique. By means of Cole‐Cole presentation comparison is made between the susceptibility functions. As it has been established that in order to characterise the large bulk of experimental data on solids and liquids functions requiring two characteristic parameters are required comparison is made between the Havriliak‐Negami and Dissado‐Hill expressions, which are of this form, and typical experimental results. It is concluded that the latter expression is more applicable.