Ultralow Loss CaMgGeO4 Microwave Dielectric Ceramic and Its Chemical Compatibility with Silver Electrodes for Low-Temperature Cofired Ceramic Applications
Ultralow Loss CaMgGeO4 Microwave Dielectric Ceramic and Its Chemical Compatibility with Silver Electrodes for Low-Temperature Cofired Ceramic Applications
复制标题
超低损耗 CaMgGeO4 微波介质陶瓷及其与低温共烧陶瓷应用银电极的化学兼容性
DOI：
10.1021/acssuschemeng.8b00220
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发表时间：
2018
影响因子：
8.4
通讯作者：
Hill Arthur E.
中科院分区：
文献类型：
--
作者：
Xiang Huaicheng;Li Chunchun;Jantunen Heli;Fang Liang;Hill Arthur E.
采用固相法制备了一种具有橄榄石结构的超低介电损耗共烧CaMgGeO4介电材料。通过X射线衍射图、Rietveld精细结构和微观结构表征了合成材料的特性。CaMgGeO4陶瓷属于具有Pbmn族空间群的斜方晶系。在1300℃下烧结6h，陶瓷的致密化程度为96.5%，在15.5 GHz频率下的超高品质因数(Q×f)为124 900 GHz(tanδ=1.24×10-4)，介电常数(εr)为6.71，谐振频率温度系数(τf)为73.7ppm/°C，平均热膨胀系数为12.4ppm/°C。添加5wt%B_2O_3后，−陶瓷的烧结温度从1300℃降至940℃。CaMgGeO4+5wt%B2O3陶瓷具有良好的微波介电性能：Q×f=102 000 GHz(16.4 GHz)，εr=5.8，τf=−64.7ppm/°C。此外，CaMgGeO4陶瓷不与银电极发生反应，这对低温共烧陶瓷多层微波器件具有一定的优势。
A new ultralow dielectric loss cofired CaMgGeO4dielectric material with olivine structure was fabricated by the solid-state route. The X-ray patterns, Rietveld refinement, and microstructure revealed the characteristics of the synthesized material. CaMgGeO4ceramic belongs to the orthorhombic system with aPbmnspace group. Sintered at 1300 °C for 6 h, the ceramic exhibited a densification of 96.5%, an ultrahigh quality factor (Q × f) of 124 900 GHz (tan δ = 1.24 × 10–4) at a frequency of 15.5 GHz, a permittivity (εr) of 6.71, and a temperature coefficient of resonant frequency (τf) of −73.7 ppm/°C, and the average coefficient of thermal expansion of CaMgGeO4was 12.4 ppm/°C. The sintering temperature of the CaMgGeO4ceramic was reduced from 1300 to 940 °C with the addition of 5 wt % B2O3. The CaMgGeO4+ 5 wt % B2O3ceramics exhibited favorable microwave dielectric performances:Q × f= 102 000 GHz (at 16.4 GHz), εr= 5.80, and τf= −64.7 ppm/°C, respectively. In addition, the CaMgGeO4ceramic did not react with Ag electrodes, which could be advantageous in low-temperature cofired ceramic multilayer microwave devices.