SCALING PARALLELS IN THE NON-DEBYE DIELECTRIC-RELAXATION OF IONIC GLASSES AND DIPOLAR SUPERCOOLED LIQUIDS

We compare the dielectric response of ionic glasses and dipolar liquid s near the glass transition. Our work is divided into two parts. In th e first section we examine ionic glasses and the two prominent approac hes to analyzing the dielectric response. The conductivity of ion-cond ucting glasses displays a power law dispersion sigma(omega)proportiona l to omega(n), where n approximate to 0.67, but frequently the dielect ric response is analyzed using the electrical modulus M(omega)=1/epsi lon(omega), where epsilon*(omega)=epsilon(omega)-i sigma(omega)/omega is the complex permittivity. We reexamine two specific examples where the shape of M(omega) changes in response to changes in (a) temperat ure and (b) ion concentration, to suggest fundamental changes in ion d ynamics are occurring. We show, however, that these changes in the sha pe of M(omega) occur in the absence of changes in the scaling propert ies of ate), for which rt remains constant. in the second part, we exa mine the dielectric relaxation found in dipolar liquids, for which eps ilon(omega) likewise exhibits changes in shape on approach to the gla ss transition. Guided by similarities of M(omega) in ionic glasses an d epsilon(omega) in dipolar liquids, we demonstrate that a recent sca ling approach proposed by Dixon and co-workers for epsilon(omega) Of dipolar relaxation also appears valid for M(omega) in the ionic case. While this suggests that the Dixon scaling approach is more universal than previously recognized, we demonstrate how the dielectric respons e can be scaled in a linear manner using an alternative data represent ation..