Low temperature firing and microwave dielectric properties of Bi_4−xGe₃O_12−1.5x ceramics

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• 作者：Xing-Hua Ma^a ; Sang-Hyo Kweon^a ; Sahn Nahm^a ; ^b ; ^c ; ^{snahm@korea.ac.kr} ; Chong-Yun Kang^b ; ^c ; Seok-Jin Yoon^c ; Young-Sik Kim^d
• 关键词：Bi4&minus ; xGe3O12&minus ; 1.5xceramics ; Bi2O3 deficiency ; Low-temperature firing ; Microwave dielectric properties
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：1 February 2017
• 年：2017
• 卷：43
• 期：2
• 页码：2801-2806
• 全文大小：1122 K
• 卷排序：43

文摘

Dense Bi4Ge3O12 ceramics sintered at 850 °C had a relative permittivity (εr) of 15.7, temperature coefficient of resonant frequency (τf) of −24.2 ppm/°C, and quality factor (Q×f) of 28,361 GHz. However, because of the existence of Bi12GeO20 as a secondary phase, the microwave dielectric properties of Bi4Ge3O12 would be degraded. Therefore, to avoid the formation of the Bi12GeO20 secondary phase, Bi2O3-deficient Bi4-xGe3O12-1.5x ceramics with 0.1≤x≤0.6 were sintered at 850 °C. A single phase of Bi3.6Ge3O11.4 (x=0.4) ceramic sintered at 850 °C for 5 h without any secondary phase exhibited suitable microwave dielectric properties for a ceramic substrate: εr=14.9, τf =−9.5 ppm/°C, and Q×f=53,277 GHz.