Influence of additives on the electrical properties of dense SnO2-based ceramics

Abstract

Highly densified 0.99 SnO2-0.01 CuO-based ceramics with antimony, tantalum, or niobium oxides as additives have been prepared. Samples have been characterized by dc conductivity and complex impedance spectroscopy as a function of temperature and by current density as a function of electric field. Microstructures have been analyzed by scanning electron microscopy, electron microprobe, and Auger spectroscopy. The electrical properties of Ta- and Nb-doped ceramics are grain boundary controlled at least at low temperature. Sb-doped materials show a different electrical behavior due to the presence of a segregation layer of antimony which inhibits grain boundary effects.