Dielectric loss spectra ε″(ω) of 11 different glass-forming materials measured in the frequency range 10-3 to 106 Hz and at various temperatures were analyzed within the framework of a Gaussian distribution of independently relaxing domains as described by Chamberlin. The relaxation time distribution G(ln τ) derived from this model is shown to be paralleled by the results of an unbiased numerical transform of ε″(ω) into the most appropriate G(ln τ). Deviations of loss spectra from a power law of the form log(ε″) α log(ω) are well accounted for by the cluster-model and appear to an inherent feature of the α-process. However, the values obtained for the scaled cluster sizes x0 = ξ/σ are too small to be compatible with the anticipated Gaussian probability density of cluster sizes, hence the applicability of the proposed dielectric function does not necessarily justify all assumptions of the model.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry