SnO_(2)掺杂Ba_(0.6)Sr_(0.4)TiO_(3)陶瓷的改性机理与介电性能调控研究  

Modification Mechanism and Dielectric Property Regulation of SnO_2-Doped Ba_(0.6S)r_(0.4)TiO_(3) Ceramics

作　　者：张涛 孙兰兰[2] 王梅 刘佳[1] 李敏 冯家乐[1] ZHANG Tao;SUN Lanlan;WANG Mei;LIU Jia;LI Min;FENG Jiale(College of Materials Science and Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;College of Science,Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]西安科技大学材料科学与工程学院,陕西西安710054 [2]西安科技大学理学院,陕西西安710054

出　　处：《压电与声光》2024年第4期511-518,共8页Piezoelectrics & Acoustooptics

基　　金：国家自然科学基金资助项目(No.52174151,No.11974275);陕西省联合基金重点资助项目(2021JML-05)。

摘　　要：钛酸锶钡(Ba_(r)Sr_(1-r)TiO_(3),BST)铁电材料具有良好的介电、铁电、热释电性能,因而成为动态随机存储器、微波调谐器及移相器等应用中的重要材料之一。采用固相烧结法制备(1-r)Ba_(0.6)Sr_(0.4)TiO_(3)-rSnO_(2)(BST-Sn)陶瓷,通过X线衍射、扫描电镜及LCR数字电桥测试系统,并结合第一性原理理论计算研究不同SnO_(2)掺杂量对BST体系微观结构和介电性能的影响。结果表明,随着SnO_(2)掺杂量的增加,BST晶格常数c与a的比(晶轴比c/a)减少,材料禁带宽度增大。当SnO_(2)掺杂量(摩尔比)为0.05时,其带隙达到最大值(1.889 eV)。能带与态密度结果表明,其带隙增大是由Ti原子的3d轨道向高能方向移动所致,实验制备出纯BST陶瓷的介电常数为3 227,SnO_(2)的引入降低了BST陶瓷的介电常数。Barium strontium titanate(Ba_rSr_(1-r)TiO_3,BST) ferroelectric material is considered an important material in dynamic random access memory,microwave tuner,phase shifter,and other applications because of its good dielectric,ferroelectric,and pyroelectric properties.In this study,the(1-r)Ba_(0.6)Sr_(0.4)TiO_3-rSnO_2(BST-Sn) ceramics were prepared via the solid-phase sintering method.The effects of different contents of SnO_(2) on the microstructure and dielectric properties of the BST system were examined via X-ray diffraction,scanning electron microscopy,and the LCR digital bridge test system.The theoretical calculation results show that the ratio of lattice constant c to lattice constant a of BST decreases and the band gap increases with an increase in the incorporation ratio of SnO_2.When the doping ratio of SnO_(2) is 0.05,the band gap reaches a maximum of 1.889 eV.The results of band and state density show that an increase in band gap is caused by the movement of Ti atoms' 3d orbitals towards high energy.Secondly,the dielectric constant of pure BST ceramics,prepared experimentally,is 3 227,and the introduction of SnO_(2) reduces the dielectric constant of BST ceramics.

关 键 词：第一性原理 SnO_(2)掺杂BST BST陶瓷 电子结构 固相烧结法 

分 类 号：TN384[电子电信—物理电子学]