Effect of Zn2SnO4 on the sintering and electrical properties of SnO2 ceramics

SnO2 ceramics with relative density about 98 % were obtained based on the addition of Zn2SnO4. The shrinkage of the ceramic samples increased sharply and got a saturated value about 13.3 % with doping more than 0.2 mol% Zn2SnO4. In the dielectric spectra, no relaxation peaks were observed and no deep trap states could be detected from 50–300 °C and 40–5 M Hz. Thus, the oxygen vacancies may not be necessary for the densification of SnO2 ceramics during sintering process. For all the samples, nonlinear electrical properties were observed and the breakdown electrical fields are in good agreement with the barrier height. With increasing Zn2SnO4 content, the activation energies Ea for O− or O2− adsorbed at grain boundary decreased and the doping of Zn2SnO4 may be an important reason for the improve of grain conductivity and formation of Schottky barrier.