Influence of microstructure on microwave dielectric properties of ZnTa2O6 ceramics with low dielectric loss

The microwave dielectric properties and the morphology of ZnTa2O6 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 epsilon(r) values range from 29.5 to 34.5 depending on the increase of the relative density. The maximum Q(.)f value obtained in this Study is 79 308 GHz when the sample is sintered in air at 1400 degreesC for 10 h. The tau(f) values are approximately 9 ppm/degreesC 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. (C) 2002 Elsevier Science B.V. All rights reserved.