Characterisation of the surface conductivity of glassy materials by means of impedance spectroscopy measurements

Abstract The phenomenon of tin dioxide doping by antimony, Sb(V), atoms in semiconductive glazes is discussed. In particular, the impedance spectra of the glaze surface at room temperature were experimentally determined, and the results were analysed in terms of equivalent circuits. The parameters resulting from the fitting procedure were related to the SnO2/Sb(V) relative content, the SnO2/Sb (V) percentage in the glaze, and the microstructure as observed by SEM. It is proposed that the addition of SnO2 and Sb2O3 to a common glaze for ceramic tile results in a semiconductive continuous phase, whose electrical characteristics fulfil the antistatic floor regulation, as far as surface conductivity is concerned. As a whole the obtained results suggest that the thermal cycle used in fast firing technology is capable to promote the oxidation of Sb2O3 to Sb2O4, resulting in a sufficient amount of Sb(V) capable of generating a semiconductive behaviour of the SnO2 crystalline phase dispersed in the glaze. © 1998 Elsevier Science Limited. All rights reserved.