Sintering effect on electrical properties of ZnO-V2O5-MnO2-Nb2O5 ceramics

The microstructure and electrical properties of quaternary ZnO-V₂O₅-MnO₂-Nb₂O₅ ceramics were investigated at different sintering temperature (875-950 °C). The average grain size increased from 4.4 μm to 9.6 μm with increasing sintering temperature. The breakdown field decreased from 6991 V/cm to 943 V/cm with increasing sintering temperature. Proper sintering for quaternary ZnO-V₂O₅-MnO₂-Nb₂O₅ ceramics led to surprisingly high nonlinear coefficient (50). The donor concentration increased from 3.33 × 10¹⁷ cm⁻³ to 7.64 × 10¹⁷ cm⁻³ with increasing sintering temperature and the barrier height exhibited the maximum value (1.07 eV) at 900 °C.