Tailoring of Microwave Dielectric Properties in (1−x)ZnTa₂O₆-xNiNb₂O₆Ceramics

The composite ceramics of (1−x)ZnTa2O6-xNiNb2O6 (x = 0–1.0) were prepared by solid-state route, and the effects of x values on the microwave dielectric properties and microstructures of the ceramics were investigated in this work. The results show that two structure regions were observed in XRD patterns as x ranged from 0 to 1.0 and the sintering temperature is 1275°C. SEM results indicate that uniform and densified surfaces can be observed for all samples. Both of the dielectric constants and Q × f values of the composite ceramics decreased with increasing x values. However, The τf values of the composite ceramics present a non-linear phenomenon, and can be tailored by controlling the x values, and a zero temperature coefficient of resonant frequency can be expected at x = 0.4–0.5.