Grain and grain boundaries contributions to dielectric relaxation of the clay-based ceramics

Abstract

The current paper is a complementary dielectric study on the clay-based ceramics (CBC) to investigate the contribution of grain and grain boundaries to the dielectric relaxations. The dielectric measurements were carried out on the ceramic composed of 50 wt.% clay and 50 wt.% nepheline syenite) over wider ranges of frequency and temperature, using the advanced broadband dielectric spectrometer. Dielectric spectra suggested that the temperature has a significant effect on the electrical microstructure of CBC. They show the existence of two relaxation process associated to the grain boundaries (GBs) and grains in low- and high-temperature regions, respectively. The relaxation process associated with grain is more predominating over GBs relaxation over the temperature range studied. Interestingly, we reported an anomaly feature in dielectric behavior of CBC at − 40 °C at which all dielectric properties changed abruptly.