Structure characteristics and enhanced microwave dielectric properties of Ba(Mg1/3Nb2/3)O3–Mg2SiO4 composite ceramics with a tunable τf
Structure characteristics and enhanced microwave dielectric properties of Ba(Mg1/3Nb2/3)O3–Mg2SiO4 composite ceramics with a tunable τf
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δf可调Ba(Mg1/3Nb2/3)O3-Mg2SiO4复合陶瓷的结构特征及增强微波介电性能
DOI：
10.1016/j.ceramint.2022.06.101
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发表时间：
2022
影响因子：
5.2
通讯作者：
Futian Liu
中科院分区：
文献类型：
--
作者：
Jian Li;Yuanyuan Zhou;Jiangnan Wu;Futian Liu
广泛应用于5G网络的微波通信器件的性能在很大程度上取决于制造中使用的介质陶瓷的性能，要求其具有合适的介电常数（ε r）、高Q × f值和近零的谐振频率温度系数（τ f）。本文研究了（1- x）Ba（Mg 1/3 Nb 2/3）O3-xMg 2SiO 4（x = 0.1，0.2，0.3，0.4，0.5）复相陶瓷材料。Ba（Mg 1/3 Nb 2/3）O3和Mg 2SiO 4由于晶体结构和配位关系的不同，可以共存而不出现非预期的物相。Ba（Mg 1/3 Nb 2/3）O3的烧结行为和结构变化与微波介电性能密切相关。适量Mg 2 SiO 4的引入促进了Ba（Mg 1/3 Nb 2/3）O3的烧结，在1420 °C烧结x = 0.3的样品获得了最大的Q × f值，为110，000 GHz。由于Mg 2SiO 4的低介电损耗和相反符号的τ f值，该复合陶瓷成功地将τ f值调整到接近于零，同时保持了高的Q × f值。但由于Ba（Mg 1/3 Nb 2/3）O3中B位阳离子的“振颤”效应和氧八面体对称性的增强，ε r和τ f的实验测量值与理论计算值有很大差异.键价分析和拉曼振动光谱结果证实了这些结构变化。在1420 °C烧结的0.6 Ba（Mg 1/3 Nb 2/3）O3 - 0.4 Mg 2 SiO 4陶瓷具有良好的微波介电性能：ε r = 18.9，Q × f = 910 0 0 GHz（8.0 16 GHz），τ f = 2.6 ppm/°C，在微波通信领域具有良好的应用前景。
The performance of microwave communication devices widely used in 5G network is strongly determined by the properties of dielectric ceramics used in the fabrication, which are required to have a suitable dielectric constant ( ε r ), high Q × f value and near-zero temperature coefficient of resonant frequency ( τ f ). In this work, (1- x )Ba(Mg 1/3 Nb 2/3 )O 3 – x Mg 2 SiO 4 ( x = 0.1, 0.2, 0.3, 0.4, 0.5) composite ceramics meeting the application requirements have been developed and investigated. Ba(Mg 1/3 Nb 2/3 )O 3 and Mg 2 SiO 4 could coexist without any unexpected phases due to the different crystal structures and coordination relationship. The sintering behavior and the structural changes of Ba(Mg 1/3 Nb 2/3 )O 3 were specifically relevant to the microwave dielectric properties. Introducing appropriate Mg 2 SiO 4 content promoted the sintering of Ba(Mg 1/3 Nb 2/3 )O 3 and the maximum Q × f value of 110,000 GHz was obtained at the sample with x = 0.3 sintered at the optimized temperature of 1420 °C. Due to the low dielectric loss and the opposite sign τ f value of Mg 2 SiO 4 , the composite ceramic successfully adjusted the τ f value to near zero while maintaining a high Q × f value. However, the experimentally measured values of ε r and τ f were significantly different from the theoretically calculated values due to the “rattling” effect of B-site cations and the enhanced symmetry of oxygen octahedra in Ba(Mg 1/3 Nb 2/3 )O 3 . These structural changes were confirmed by the results of bond valence analysis and Raman vibration spectra. The 0.6Ba(Mg 1/3 Nb 2/3 )O 3 –0.4Mg 2 SiO 4 ceramic sintered at 1420 °C exhibits competitive microwave dielectric properties: ε r = 18.9, Q × f = 91,000 GHz (at 8.016 GHz) and τ f = 2.6 ppm/°C, which indicates it a promising application prospect of microwave communication.