Sintering behavior,phase composition,microstructure,and dielectric characteristics of garnet-type Ca_(3)Fe_(2)Ge_(3)O_(12) microwave ceramics  

作　　者：Guoqiang He Yanjun Liu Huanfu Zhou Xiuli Chen 

机构地区：[1]Key Laboratory of Nonferrous Materials and New Processing Technology,Ministry of Education,School of Materials Science and Engineering,Guilin University of Technology,Guilin,541004,China

出　　处：《Journal of Materiomics》2023年第3期472-481,共10页无机材料学学报（英文）

基　　金：supported by Natural Science Foundation of China(Grant Nos.61761015,11664008);Natural Science Foundation of Guangxi(Grant No 2018GXNSFFA050001);the High Level Innovation Team and Outstanding Scholar Program of Guangxi Institutes.

摘　　要：This paper describes the solid-state production of a unique yellowish-grey microwave dielectric ceramic,Ca_(3)Fe_(2)Ge_(3)O_(12)(CFG).Rietveld refinement demonstrated that CFG corresponds to a cubic system(space group 230:Ia 3 d).The relative density of the ceramic initially increased and then decreased with the sintering temperature,reaching a maximum of 96.92%at 1330℃.According to scanning electron mi-croscopy and energy-dispersive spectroscopy results,the CFG ceramic grains are spherical and consistent in size;furthermore,they have distinct grain boundaries and a uniform distribution of the four con-stituent elements.The CFG ceramic has a superior crystal structure and a high crystallinity,according to transmission electron microscopy.Raman spectroscopy revealed that the Q×f value of the ceramic and the full width at half maximum of the Raman peak are negatively correlated.The ceramic possesses the best overall dielectric characteristics after sintering at 1330℃for 4 h:ε_(r)=10.31,Q×f=82636 GHz,andτ_(f)=-45.66×10^(-6)℃^(-1),showing that it is a promising candidate for use in mobile devices.

关 键 词：Low permittivity Garnet-type structure Microwave dielectric properties Ca_(3)Fe_(2)Ge_(3)O_(12) 

分 类 号：TQ174.1[化学工程—陶瓷工业]