Relationship between structure and microwave dielectric properties of Li_(3)Mg_(4)Nb_(1-x)Ta_(x)O_(8)ceramics  

作　　者：Chongsheng Wu Kui Liu Honglan Lai Fang Xu 

机构地区：[1]School of Mechanical and Electrical Engineering,Chengdu University of Technology,Chengdu,Sichuan,610059,China [2]School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu,610054,China [3]State Key Laboratory of Environment-friendly Energy Materials,Southwest University of Science and Technology,Mianyang,621010,China

出　　处：《Journal of Materiomics》2024年第1期245-252,共8页无机材料学学报（英文）

基　　金：supported by the National Natural Science Foundation of China(Grant No.52202341).

摘　　要：Herein,the sintering behavior and dielectric properties of Ta5+-doped Li3Mg4NbO8 ceramics were investigated by solid-phase reactions in combination with first-principles calculations.In particular,Li_(3)Mg_(4)Nb_(0.96)Ta_(0.04)O_(8)illustrates the best dielectric properties after sintering at 1,175℃withεr=13.71±0.20,Q×f=(132,112±2,391)GHz(increased by 25%)andτf=(25.07±1.36)×10^(−6)℃^(−1).The non-intrinsic factors reflect that a small amount of Ta^(5+)doping produces a secondary phase,increased densification,and grain size,all of which optimize the dielectric properties.The dominant intrinsic factors indicate that the increase in bond ionicity,the greater polarization of Ta^(5+),and the blueshift of the Raman characteristic peak all lead to an increase inεr.The increase in lattice energy and the decrease in the damping behavior of the Nb/Ta-O bond vibrations lead to an increase in Q×f.The weakening of the Nb/TaO_(6) octahedral distortion leads to an optimization ofτf.The modified Li_(3)Mg_(4)Nb_(0.96)Ta_(0.04)O_(8) ceramics have promising applications in microwave communications.

关 键 词：FIRST-PRINCIPLES Li_(3)Mg_(4)NbO_(8) dielectric properties Lattice vibration 

分 类 号：TQ174.1[化学工程—陶瓷工业]