| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1612423 | Journal of Alloys and Compounds | 2014 | 7 Pages |
•The crystal structure of CaxZn1−xSn0.08Ti1.92Nb2O10 ceramics were analyzed.•The quantitative determination of CaxZn1−xSn0.08Ti1.92Nb2O10 ceramics were analyzed.•The typical values of ε = 53.09, Qf = 48,000 GHz, τf = 21.20 ppm/°C were obtained.
The quantitative determination and the crystal structure of CaxZn1−xSn0.08Ti1.92Nb2O10 ceramics were analyzed by X-ray diffraction, the microwave dielectric properties were investigated. The results showed that the CaxZn1−xSn0.08Ti1.92Nb2O10 ceramics contained three main phases: ZnTiNb2O8 phase, Zn0.15Nb0.30Ti0.55O2 phase and Unknown Columbite-type phase. With the increase of Ca content, the weight fraction of secondary phase Zn0.15Nb0.30Ti0.55O2 and Unknown Columbite-type phase increased. For ZnTiNb2O8, with the substitution of Ca2+ for Zn2+, the bond valence of Ti-site increased. The variation of distortion of oxygen octahedral was irregular. For Zn0.15Nb0.30Ti0.55O2, the distortion of oxygen octahedral and the bond valence of Ti-site increased with substitution of Ca2+. The increase of Ti-site bond valence led to a harder rattling of Ti cations of the specimens. As a result, the dielectric constant (ε) and the quality factor value (Qf) decreased, the temperature coefficient of resonant frequency (τf) moved to the positive direction. The typical values of ε = 53.09, Qf = 48,000 GHz, τf = 21.20 ppm/°C were obtained for CaxZn1−xSn0.08Ti1.92Nb2O10 (x = 0.02) specimens sintered at 1120 °C for 6 h. The relative low sintering temperature and high dielectric properties in microwave range make these ceramics promising for application in multilayer ceramic capacitors.
