Non-symmetrical dielectric relaxation behaviour arising from a simple empirical decay function

Abstract

The empirical diclectric decay function y ( t ) -= exp -( f / ~~) p may be transformed analytically to give the frequency dependent complex dielectric constant if p is chosen to be 0.50. The resulting dielectric constant and dielectric loss curves are non-symmetrical about the logarithm of the frequency of maximum loss, and are intermediate between the Cole-Cole and Davidson-Cole empirical relations.Using a short extrapolation procedure, good agreement is obtained between the empirical representation and the experimental curves for the a relaxation in polyethyl acrylate. It is suggested that the present representation would have a general application to the a relaxations in other polymers.

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