Reaction sintering of nano-sized ZnO–Nb2O5 powder mixture: sintering, microstructure and microwave dielectric properties

Sintering behavior, microstructures and microwave dielectric properties of ZnNb2O6 (ZN) ceramics prepared by reaction-sintering method were investigated. The X-ray diffraction patterns of the sintered samples revealed single-phase formation with a columbite structure after 1–5 h sintering at 1,025–1,125 °C. After sintering at 1,125 °C for 5 h, the ZN ceramics with the density of 5.56 g/cm3 (98.9 % of the theoretical density) and good microwave dielectric properties of er = 23.9, Q × f = 51,000 and τf = −62 ppm/°C were obtained. The obtained results demonstrated that the reaction-sintering process is a simple and effective method to prepare the ZN ceramics for applications on microwave dielectric resonators.