Structure analysis and microwave dielectric properties of CaxZn1鈭?/sub>xSn0.08Ti1.92Nb2O10 ceramics
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- 作者：Lingxia Li ; Haocheng Cai ; Xiaoxu Yu ; Qingwei Liao ; Zhengdong Gao
- 关键词：Ceramics ; X-ray diffraction ; Crystal structure ; Electronic properties
- 刊名：Journal of Alloys and Compounds
- 出版年：25 January, 2014
- 年：2014
- 卷：584
- 期：Complete
- 页码：315-321
- 全文大小：1869 K
文摘
The quantitative determination and the crystal structure of CaxZn1鈭?/sub>xSn0.08Ti1.92Nb2O10 ceramics were analyzed by X-ray diffraction, the microwave dielectric properties were investigated. The results showed that the CaxZn1鈭?/sub>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 (蔚) and the quality factor value (Qf) decreased, the temperature coefficient of resonant frequency (蟿f) moved to the positive direction. The typical values of 蔚 = 53.09, Qf = 48,000 GHz, 蟿f = 21.20 ppm/掳C were obtained for CaxZn1鈭?/sub>xSn0.08Ti1.92Nb2O10 (x = 0.02) specimens sintered at 1120 掳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.