Cu^(2+)离子A位取代对MgTiO_(3)陶瓷结构及介电性能的影响  

Effect of Cu^(2+)Ion A⁃Site Substitution on Structure and Dielectric Properties of MgTiO_(3) Ceramics

作　　者：杨习志 杨帆[1] 赖元明 李宝阳 王凡硕 苏桦[2] YANG Xi-Zhi;YANG Fan;LAI Yuan-Ming;LI Bao-Yang;WANG Fan-Shuo;SU Hua(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]成都理工大学机电工程学院,成都610059 [2]电子科技大学,电子薄膜与集成器件国家重点实验室,成都610054

出　　处：《无机化学学报》2022年第4期599-610,共12页Chinese Journal of Inorganic Chemistry

基　　金：稀贵金属综合利用新技术国家重点实验室开放课题(No.SKL⁃SPM⁃202021);成都理工大学科研启动基金(No.KYQD2019_07728)资助。

摘　　要：采用固相反应制备了Mg_(1-x)Cu_(x)TiO_(3)(0.00≤x≤0.20)微波介电陶瓷,研究CuO烧结助剂对MgTiO_(3)陶瓷的微观结构和微波介电性能的影响。实验结果表明,CuO中的Cu^(2+)离子会进入到MgTiO_(3)晶格中并取代Mg^(2+),形成Mg_(1-x)Cu_(x)TiO_(3)固溶体。由于液相效应,适量的CuO可以促进MgTiO_(3)陶瓷的致密化烧结,降低其烧结温度。Cu^(2+)离子的A位取代会改变样品的TiO_(6)八面体扭曲度。随着Cu^(2+)离子含量的增加,会使MgTiO_(3)陶瓷的结构稳定性降低。随着CuO含量的增加,晶粒的不均匀生长和液相的出现导致样品的品质因数(Qf)下降。同时,Mg_(1-x)Cu_(x)TiO_(3)陶瓷的相对密度、结构稳定性和平均共价度的降低也会恶化陶瓷的Qf值。样品的介电常数(ε_(r))与离子极化率、杂相和TiO_(6)八面体扭曲度相关。样品的谐振频率温度系数(τ_(f))随TiO_(6)八面体扭曲度的增加而减小。当x=0.08时,样品可在1150℃实现致密化烧结,且τ_(f)值改善至-3.4×10^(-5)℃^(-1)。Mg_(1-x)Cu_(x)TiO_(3)(0.00≤x≤0.20)microwave ceramics were prepared by the solid⁃state reaction method.The effects of CuO sintering aids on the microstructure and microwave dielectric properties of MgTiO_(3) ceramics were investigated.It was shown that the Cu^(2+)ions could enter the MgTiO_(3) lattice and substitute Mg^(2+)ions forming Mg_(1-x)Cu_(x)TiO_(3) solid solution.A moderate amount of CuO can promote the densification sintering of MgTiO_(3) ceramics and reduce the sintering temperature due to the liquid phase.The A⁃site substitution of Cu^(2+)ions alters the distortion of the TiO_(6) octahedra.With the increase of Cu^(2+)ionscontent in MgTiO_(3) ceramics,the structural stability was weak⁃ened.With the addition of CuO content,the quality factor(Qf)of the sample decreased owing to inhomogeneous grain growth and the appearance of the liquid phase.Meanwhile,the reduction of relative density,structural stability,and average covalency of Mg_(1-x)CuxTiO_(3) ceramics would deteriorate the Qf value of the sample.The dielectric con⁃stants(εr)of samples were related to the ionic polarizability,impurity phase,and TiO6 octahedra distortion.The tem⁃perature coefficients of resonant frequency(τf)decreased with the increase of TiO_(6) octahedra distortion.When x=0.08,the sample could achieve densification sintering at 1150℃and theτf value was improved to-3.4×10^(-5)℃^(-1).

关 键 词：微波介电陶瓷 结构 介电性能 

分 类 号：TQ174[化学工程—陶瓷工业]