Universal scaling of the dielectric relaxation in dipole liquids and glasses

Abstract

A long-standing puzzle in the relaxation of glasses has been the upward curvature of the imaginary part of the dielectric constant on the high-frequency side of the primary relaxation peak. Similarly, a puzzle of several years' standing has been the 'universal scaling' of the dielectric constant observed in dipole glasses; what has been difficult to explain is the fact that the departure from the apparent Kohlrausch-Williams-Watts (KWW) form for the relaxation follows the same general scaling function as the KWW portion near the relaxation peak. This is shown to be easily interpretable in terms of a crossover from independent 'hopping' transitions at high frequencies to correlated hopping transitions near the peak, provided the crossover frequency and high-frequency approximate power are both related to the peak frequency and KWW exponent respectively. Such a specific derivation has already been accomplished in electronic and ionic hopping conduction systems; its analogue for dipole glasses is consistent with the observed scaling behaviour.