(Li_(0.5)Nb_(0.5))^(3+)共取代对MgAl_(2)O_(4)介电性能的影响  

Effects of(Li_(0.5)Nb_(0.5))^(3+) co-substitution on microwave dielectric characteristics of MgAl_2O_4 ceramics

作　　者：殷俊 杨习志 赖元明 张芹 戚聪 李潇 苏桦 巫崇胜 蒋刚 YIN Jun;YANG Xi-zhi;LAI Yuan-ming;ZHANG Qin;QI Cong;LI Xiao;SU Hua;WU Chong-sheng;JIANG Gang(School of Mechanical and Electrical Engineering,Chengdu University of Technology,Chengdu 610059,China;State Key Laboratory of Electronic Thin Films and Integrated Devices,University of Electronic Science and Technology of China,Chengdu 610054,China)

机构地区：[1]School of Mechanical and Electrical Engineering,Chengdu University of Technology,Chengdu 610059,China [2]State Key Laboratory of Electronic Thin Films and Integrated Devices,University of Electronic Science and Technology of China,Chengdu 610054,China

出　　处：《Journal of Central South University》2023年第5期1461-1468,共8页中南大学学报（英文版）

基　　金：Project(SKL-SPM-202021) supported by the State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals,China;Project(2023YFQ0082) supported by Sichuan Science and Technology Program,China;Project(EFMD2022005Z) supported by Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices,China。

摘　　要：采用固相反应法制备了MgAl_(2-x)(Li_(0.5)Nb_(0.5))_(x)O_(4)介电陶瓷,分析了样品的晶体结构特征、物相组成以及介电性能。XRD精修结果显示,MgAl_(2)O_(4)和Mg_(5)Nb_(4)O_(15)形成了一个稳定的两相系统。在1550℃烧结时,致密度随着(Li_(0.5)Nb_(0.5))^(3+)的含量增大而减小。品质因数Q_(f)的变化趋势与致密度、填充分数以及共价度密切相关。另外,谐振频率温度系数τ_(f)主要受Al位键价影响。MgAl_(2-x)(Li_(0.5)Nb_(0.5))_(x)O_(4)陶瓷在1550℃烧结4 h后拥有最优介电性能:ε_(r)=8.21,Q_(f)=81600 GHz和τ_(f)=-94×10^(-6)℃^(-1)。Nominal compositions MgAl_(2-x)(Li_(0.5)Nb_(0.5))_(x)O_(4)(x=0-0.20) microwave dielectric ceramics were synthesized via the traditional solid-state reaction.The crystal structural characteristics,crystalline phases,and microwave dielectric properties were investigated.Rietveld refinement results showed that MgAl_(2)O_(4) and Mg_5Nb_(4)O_(15) form a stable two-phase system.Densification of the specimens decreases monotonically with the increase of(Li_(0.5)Nb_(0.5))^(3+) content when sintered at 1550 ℃.The variation tendency of quality factor(Q_(f)) is closely related to the densification,packing fraction and covalency.Likewise,the bond valence of the Al-site is responsible for the temperature coefficient of resonance frequency(τ_(f)).MgAl_(2-x)(Li_(0.5)Nb_(0.5))_(x)O_(4) ceramic with x=0.04 can be well densified by sintering at 1550 ℃ for 4 h and exhibits optimum microwave dielectric properties with ε_(r)=8.21,Q_(f)=81600 GHz,and τ_(f)=-94×10^(-6) ℃^(-1).

关 键 词：微波介电陶瓷 共取代 MgAl_(2)O_(4)陶瓷 

分 类 号：TQ174.1[化学工程—陶瓷工业]