Synthesis of Zn3Nb2O8 ceramics using a simple and effective process

Synthesis of Zn₃Nb₂O₈ ceramics using a simple and effective reaction-sintering process was investigated. The mixture of ZnO and Nb₂O₅ was pressed and sintered directly without any prior calcination. Single-phase Zn₃Nb₂O₈ ceramics could be obtained. Density of these ceramics increased with soaking time and sintering temperature. A maximum density 5.72 g/cm³ (99.7% of the theoretical density) was found for pellets sintered at 1170 °C for 2 h. Pores were not found and grain sizes >20 μm were observed in pellets sintered at 1170 °C. Abnormal grain growth occurred and grains >50 μm could be seen in Zn₃Nb₂O₈ ceramics sintered at 1200 °C for 2 h and 1200 °C for 4 h. Reaction-sintering process is then a simple and effective method to produce Zn₃Nb₂O₈ ceramics for applications in microwave dielectric resonators.