Effects of Ti{sup}(4+) Substitution on Microstructure and Microwave Dielectric Properties of ZnNb{sub}(2(1-x))Ti{sub}xO{sub}(6-3x) Ceramics

摘要

The microstructure and microwave dielectric properties of dielectric ceramics comprised of ZnNb{sub}(2(1-x))TlxO{sub}(6-3x) (x = 0 ～ 1) were investigated systematically using X-ray powder diffraction, SEM and a network analyzer in this study. The results showed that four phases were observed in this system. The dielectric properties at microwave frequencies exhibit a significant dependence on the composition and crystal structure of the ceramics. The dielectric constant (ε{sub}r) of ZnNb{sub}(2(1-x))Ti{sub}xO(6-3x) ceramics increases with increasing Ti content and the quality factors (Q×f) significantly decreased. However, the temperature coefficient of resonant frequency (τ{sub}f) changes from -59.08 ppm/°C at x = 0 to + 25.1 ppm/°C at x = 1, and a zero temperature coefficient of resonant frequency (τ{sub}f) for this ceramics system was obtained at x = 0.84.