预烧温度对BaTiO_3基X7R陶瓷相结构和介电性能的影响  

Effect of Calcination Temperature on Phase Structure and Dielectric Properties of BaTiO_3-Based X7R Ceramics

作　　者：陈力颖[1,2] 吴顺华[1,2] 王爽[1] 王国庆[1] 刘明媚[3] 赵国捷[3] 

机构地区：[1]天津大学电子信息工程学院,天津300072 [2]天津大学先进陶瓷与加工技术教育部重点实验室,天津300072 [3]天津大学管理学院,天津300072

出　　处：《稀有金属材料与工程》2008年第A01期90-93,共4页Rare Metal Materials and Engineering

摘　　要：采用传统电子陶瓷工艺制备了符合X7R指标的BaTiO_3陶瓷系统,研究了预烧过程对该系统结构和介电性能的影响。XRD和SEM分析表明,对BaTiO_3粉料的预烧增大了晶粒尺寸并增加了c/a比,预烧过程通过增加c/a比提高了铁电性,极大地提升了介电常数,但是由于电畴重定向的驰豫机制也导致了损耗角的少量增加。没有经过预烧的BaTiO_3陶瓷(1240℃烧结),其相结构近似立方相(c/a=1.0005),而把BaTiO_3粉料经过预烧(1200℃),同样烧结条件(1240℃)的BaTiO_3陶瓷相结构为四方相c/a=1.0030。BaTiO_3系统在1200℃预烧和1240℃烧结得到的样品具有满足X7R指标的优良介电性能,其介电性能为:ε_r≥4500,⊿ε_r/ε_(r25)≤±15%(-55～125℃),tanδ≤0.012(25℃)。The BaTiO3 ceramics meeting the X7R specifications were prepared by conventional electronic ceramics technology. The microstructure and dielectric properties of the ceramics were studied by varying the calcination temperatures. The calcinations of the BaTiO3 raw powders increased the grain size and the c/a ratio of the ceramics. The dielectric constant increased accordingly. A high loss of tangent was resulted from the relaxation of domain reorientation. The uncalcined BaTiO3 ceramics sintered at 1240 ~C were the cubic phase （c/a=1.0005） and the calcined BaTiO3 ceramics at 1200 ℃ were the tetragonal phase （c/a=1.0030） sintered at the same temperature （1240 ℃）. The BaTiO3 ceramics meeting the X7R specifications were obtained at the calcination temperature of 1200 ℃ and the sintering temperature of 1240 ℃. The dielectric properties were εr≥4500, △εr/εr25≤±15%（-55～125 ℃） and tanδ≤0.012（25 ℃）, respectively.

关 键 词：BATIO3 介电性能 X7R 预烧温度 

分 类 号：TQ174.1[化学工程—陶瓷工业]