Improvement of non-linear characteristics of multicomponent ZnO-based ceramics containing Nb2O5

The combined effect of minor variations in the Nb₂O₅ content and initial particle size on the current-voltage characteristics and energy handling capability of ZnO-based composites is reported. Samples containing 0.2 wt.% of Nb₂O₅ along with other additive oxides, prepared as a finely milled mixture, were found to possess the best overall properties, characterized by high nonlinearity index (≃60), low leakage current (0.6-1.2 μA/cm²) long life (>150 y), among the samples studied. Addition of Nb₂O₅ above 0.2 wt.%, maintaining other parameters constant, was found to degrade the electrical characteristics due to the excessive formation of Zn₃Nb₂O₈ spinel phase