Structure analysis and microwave dielectric properties of CaxZn1−xSn0.08Ti1.92Nb2O10 ceramics
Structure analysis and microwave dielectric properties of CaxZn1−xSn0.08Ti1.92Nb2O10 ceramics
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DOI：
10.1016/j.jallcom.2013.09.084
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发表时间：
2014-01
影响因子：
6.2
通讯作者：
Lingxia Li;Cai Haocheng;Xiaoxue Yu;Q. Liao;Gao Zhengdong
中科院分区：
文献类型：
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作者：
Lingxia Li;Cai Haocheng;Xiaoxue Yu;Q. Liao;Gao Zhengdong
采用X射线衍射法对CaxZn 1 − xSn 0. 08 Ti 1. 92 Nb 2 O 10陶瓷进行了定量测定和晶体结构分析，并对其微波介电性能进行了研究。结果表明：CaxZn 1 − xSn0.08Ti1.92Nb2O10陶瓷主要由ZnTiNb 2 O 8、Zn0.15Nb0.30Ti0.55O2和未知的铌铁矿型相组成。随着Ca含量的增加，第二相Zn0.15Nb0.30Ti0.55O2和未知铌铁矿型相的质量分数增加。对于ZnTiNb_2O_8，随着Ca ~（2+）取代Zn ~（2+），Ti位的键价增加。氧八面体畸变的变化是不规则的。对于Zn_（0.15）Nb_（0.30）Ti_（0.55）O_2，Ca ~（2+）的取代增加了氧八面体的畸变和Ti位的键价。Ti位键价的增加导致样品中Ti阳离子的振动强度增加。结果表明，介电常数ε和品质因数Qf减小，谐振频率温度系数τf向正方向移动。在1120 °C烧结6 h的CaxZn 1 −xSn0.08Ti1.92Nb2O10（x= 0.02）样品的典型值为ε= 53.09，Qf = 48，000 GHz，τf= 21.20 ppm/°C。该陶瓷具有较低的烧结温度和较高的微波介电性能，在多层陶瓷电容器中具有良好的应用前景。
The quantitative determination and the crystal structure of CaxZn1−xSn0.08Ti1.92Nb2O10ceramics were analyzed by X-ray diffraction, the microwave dielectric properties were investigated. The results showed that the CaxZn1−xSn0.08Ti1.92Nb2O10ceramics contained three main phases: ZnTiNb2O8phase, Zn0.15Nb0.30Ti0.55O2phase and Unknown Columbite-type phase. With the increase of Ca content, the weight fraction of secondary phase Zn0.15Nb0.30Ti0.55O2and 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 ofε= 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.