B位(Mg_(1/3)Ta_(2/3))^(4+)置换对新型Sr基(Sr,Nd,Ca)TiO_3微波陶瓷结构及介电性能的影响  

B-site Substitution by(Mg_(1/3)Ta_(2/3))^(4+) on Structures and Dielectric Properties of New Sr-based(Sr,Nd,Ca)TiO_3 Microwave Ceramics

作　　者：屈婧婧[1] 魏星[1] 宋小辉[1] 袁昌来[2] 刘飞[3] QU Jing-Jing WEI Xing SONG Xiao-Hui YUAN Chang-Lai LIU Fei(Guilin University of Aerospace Technology, Department of Computer Science and Engineering, Guilin 541004, China Guilin University of Electronic Technology, School of Material Science and Engineering, Guilin 541004, China School of Mechanical and Electrical Endineering, Guilin University of Electronic Techonology, Guilin 541004, China)

机构地区：[1]桂林航天工业学院计算机科学与工程系,桂林541004 [2]桂林电子科技大学材料科学与工程学院,桂林541004 [3]桂林电子科技大学机电工程学院,桂林541004

出　　处：《无机材料学报》2017年第3期293-298,共6页Journal of Inorganic Materials

基　　金：广西自然科学基金(118286);国家自然科学基金(11464006);广西高校中青年教师基础能力提升项目(KY2016YB534)~~

摘　　要：采用固相反应法合成了(Sr_(0.2)Nd_(0.208)Ca_(0.488))Ti_(1-x)(Mg_(1/3)Ta_(2/3))_xO_3(0.2≤x≤0.5,SNCTMTx)系微波介质陶瓷,分析了SNCTMTx(0.2≤x≤0.5)陶瓷的相组成、显微结构、烧结特性和微波介电性能之间的关系。XRD晶体结构分析表明:当x=0.2时,SNCTMTx陶瓷为单一正交钙钛矿结构,当x值增为0.3~0.5时,陶瓷体呈现正交钙钛矿相、SrO与未知相多相共存状态。随着(Mg_(1/3)Ta_(2/3))^(4+)含量的增加,体系中第二相的出现及含量的改变导致εr先增后减,而Q×f值出现先降后升的原因是B位离子1:2有序度的出现与范围的增加抑制了第二相进一步恶化品质因子;此外,τf逐渐向近零方向偏移与氧八面体的畸变程度密切相关。当x=0.5时,在1530℃烧结4 h得到的SNCTMTx陶瓷微波介电性能较优:ε_r=55.3,Q×f≈7400 GHz,τf≈23.6×10^(–6)/℃。（Sr0.2Nd0.208Ca0.488il.x（Mgl/3Ta2r3）xO3 （0.2≤x≤0.5, SNCTMTx） ceramics were prepared by solid sate reaction technique. Wherein, the relation between phase compositions, microstructures, sintering properties, and microwave dielectric properties of the SNCTMTx （0.2≤x≤0.5） ceramic systems were studied. The XRD results indicated that a single phase with orthorhombic perovskite-like structure was formed in the sample with x = 0.2, and a mixed phase system was formed in the samples with given compositional range x = 0.3 - 0.5 composed of orthorhombic perovskite phase, SrO phase and unknown second phase. Additionally, the er first increased and then decreased, affected by the appearance and the content of the second phase. Meanwhile, the Qxfvalue showed down first and then up with the increase of （Mg1/3Ta2/3）4＋ content because the in- creasing degree of 1：2 ordering could suppress the reduction in quality factor. Moreover, the rf gradually shifted to near-zero direction, which resulted from the variation of the oxygen octahedral distortion. The SNCTMTx （x=0.5） ceramic sintered at 1530℃ for 4 h showed better microwave dielectric properties with er = 55.3, Q ×f≈ 7,400 GHz and rf = 23.6× 10-6/℃.

关 键 词：钙钛矿 （Mg1/3Ta2/3）4＋ 微波介电性能 （Sr0.2Nd0.208Ca0.488）TiO3 

分 类 号：TQ174[化学工程—陶瓷工业]