A low-firing melilite ceramic Ba2CuGe207 and compositional modulation on microwave dielectric properties through Mg substitution  

作　　者：Changzhi YIN Zezong YU Longlong SHU Laijun LIU Yan CHEN Chunchun LI 

机构地区：[1]College of Information Science and Engineering,Guilin University of Technology,Guilin 541004,China [2]School of Materials Science and Engineering,Nanchang University,Nanchang 330031,China [3]Guangxi Universities Key Laboratory of Non-Ferrous Metal Oxide Electronic Functional Materials and Devices,College of Material Science and Engineering,Guilin University of Technology,Guilin 541004,China

出　　处：《Journal of Advanced Ceramics》2021年第1期108-119,共12页先进陶瓷（英文）

基　　金：National Natural Science Foundation of China(No.62061011);National Key R&D Program of China(No.2017YFB0406300);Natural Science Foundation of Guangxi Zhuang Autonomous Region(No.2018GXNSFAA281253);high-level innovation team and outstanding scholar program of Guangxi institutes.

摘　　要：A melilite Ba2CuGe2O7 ceramic was characterized by low sintering temperature and moderate microwave dielectric properties.Sintered at 960℃,the Ba2CuGe2O7 ceramic had a high relative density 97%,a low relative permittivity(εr)9.43,a quality factor(Q×f)of 20,000 GHz,and a temperature coefficient of resonance frequency(τf)-76 ppm/℃.To get a deep understanding of the relationship between composition,structure,and dielectric performances,magnesium substitution for copper in Ba2CuGe2O7 was conducted.Influences of magnesium doping on the sintering behavior,crystal structure,and microwave dielectric properties were studied.Mg doping in Ba2CuGe2O7 caused negligible changes in the macroscopic crystal structure,grain morphology,and size distribution,while induced visible variation in the local structure as revealed by Raman analysis.Microwave dielectric properties exhibit a remarkable dependence on composition.On increasing the magnesium content,the relative permittivity featured a continuous decrease,while both the quality factor and the temperature coefficient of resonance frequency increased monotonously.Such variations in dielectric performances were clarified in terms of the polarizability,packing fraction,and band valence theory.

关 键 词：CERAMICS dielectric properties melilite structure compositional modulation 

分 类 号：TQ174.1[化学工程—陶瓷工业]