Microstructural and microwave dielectric properties of ZnNb2O6 ceramics prepared through microwave sintering

The microstructural and microwave dielectric properties of ZnNb2O6 ceramics prepared through conventional and microwave sintering at different temperatures have been investigated. Samples sintered at different temperatures through both methods were single phase with no second phases present. The highest densities obtained for conventional and microwave sintered samples were 93.5% (at 1150 °C) and 94.3% of the theoretical value (at 1200 °C), respectively. The relative permittivity results for samples sintered at different temperatures through both methods followed the variation in the density values. The highest values for relative permittivity (εr) for conventional and microwave sintered samples were 22.5 (at 1100 °C) and 23 (at 1200 °C), respectively. The variation of quality factor (Q×f) with sintering temperature for samples prepared through both methods is mainly dictated by the changes in grain size. The highest Q×f values for conventional and microwave sintered samples were 82688 GHz (at 1300 °C) and 52,594 GHz (at 1300 °C), respectively. There was no meaningful relation between the changes in temperature coefficient of resonant frequency (τf), and microstructural features.