Dielectric response of some ferroelectrics at ‘low’ frequencies II

Abstract

An earlier paper on the dielectric spectra of some PST ferroelectric ceramics showed ‘universal’ power law behaviour lying beneath other parallel processes such as high-frequency capacitance C _∞, direct current conductivity, Low-Frequency Dispersion and some dipolar processes. The present contribution refers to low-loss ceramics in which a novel form of ‘trans-universal’ response is observed because it is not possible to subtract a sensible value of C _∞ but instead one has to postulate a series combination of a universal dipolar element and a universal power-law element after which it becomes possible to determine C _∞. Examples of this analysis are given and a possible physical interpretation is suggested.

Key Words:

• Low frequency
• ferroelectrics
• ‘trans-universal’
• law