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 8C for 2 h. Pores were not found and grain sizes >20 mm were observed in pellets sintered at 1170 8C. Abnormal grain growth
occurred and grains >50 mm could be seen in Zn3Nb2O8 ceramics sintered at 1200 8C for 2 h and 1200 8C for 4 h. Reaction-sintering process is
then a simple and effective method to produce Zn3Nb2O8 ceramics for applications in microwave dielectric resonators.