Influence of microstructure on microwave dielectric properties of ZnTa_2O_6 ceramics with low dielectric loss

摘要

The microwave dielectric properties and the morphology of ZnTa_2O_6 ceramics prepared under different sintering conditions were studied in this work. The formation of an impurity phase was not detected by X-ray powder diffraction (XRPD) analysis, and grain growth of the samples was recognized from field emission scanning electron microscopy (FE-SEM) results when increasing the sintering temperature and sintering time. From the evaluation of microwave dielectric properties, the implied by_r values range from 29.5 to 34.5 depending on the increase of the relative density. The maximum Q centre dot f value obtained in this study is 79 308 GHz when the sample is sintered in air at 1400 deg C for 10 h. The tau_f values are approximately 9 ppm/deg C in all the samples sintered at various temperatures for 2 and 10 h. These microwave dielectric properties of the ceramics may be appropriate for a microwave dielectric resonator in satellite communication.