Article ID Journal Published Year Pages File Type
1465097 Ceramics International 2007 6 Pages PDF
Abstract

Tin dioxide varistors doped with CoO, ZnO, Ta2O5 and Cr2O3 were prepared by the mixed oxide method. Temperature dependent impedance spectroscopy revealed two different activation energies, one at low frequencies and the other at high frequencies. These activation energies were associated with the adsorption and reaction of O2 species at the grain boundary interface. We show that Cr2O3 improves the varistor properties, generating sites for the adsorption of O′ and O″ at the grain boundary region. The O′ and O″ defects are truly responsible for the barrier formation at the grain boundary interface.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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