B位复合离子取代对Na1/2Bi1/2TiO3无铅压电陶瓷介电特性的影响  

Effect of B-site complex ions substitution on dielectric properties of Na_(1/2)Bi_(1/2)TiO_3 lead-free piezoelectric ceramics

作　　者：周昌荣[1,2] 刘心宇[1,2] 

机构地区：[1]桂林电子科技大学信息材料科学与工程系,广西桂林541004 [2]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2009年第1期200-204,共5页Journal of Central South University:Science and Technology

基　　金：广西壮族自治区自然科学基金资助项目(0447092)

摘　　要：采用传统陶瓷制备方法,制备无铅新压电陶瓷材料(1-x)Na1/2Bi1/2TiO3-xNa1/2Bi1/2(Sb1/2Nb1/2)O3。利用X射线衍射,精密阻抗分析仪研究Na1/2Bi1/2TiO3陶瓷B位复合离子(Sb1/2Nb1/2)4+取代对晶体结构、弥散相变与介电弛豫行为的影响,并根据宏畴-微畴转变理论探讨该体系陶瓷产生介电弛豫的机理。研究结果表明,在所研究的组成范围内,陶瓷材料均能够形成纯钙钛矿固溶体。该体系陶瓷具有2个介电反常峰tf和tm,表现出与典型弛豫铁电体明显不同的弛豫行为,掺杂量低的陶瓷仅在低温介电反常峰tf附近表现出明显的频率依赖性,而掺杂量高的陶瓷材料在室温和tf之间都表现出明显的频率依赖性。A new lead-free piezoelectric ceramics of （1-x）Na1/2Bi1/2TiO3-xNa1/2Bi1/2（Sb1/2Nb1/2）O3 was prepared by conventional solid state reaction and the effects of B-site complex ions substitution on dielectric properties and relaxation of Na1/2Bi1/2TiO3 lead-free piezoelectric ceramics were investigated. The mechanism of relaxor behavior was also discussed according to the macro-domain to micro-domain transition theory. X-ray diffraction patterns show that （Sb1/2Nb1/2）^4＋ diffuses into the lattice of Nal/2Bi1/2TiO3 to form a solid solution with perovskite-type structure. The temperature dependence of dielectric constant reveals that the solid solution has two dielectric abnormal peaks. All samples exhibit relaxor characteristics different from classic relaxor ferroelectrics. The samples with low doping level of Na1/2Bi1/2（Sb1/2Nb1/2）O3 exhibit obvious frequency dependence only near the low temperature dielectric abnormal peak if, and the samples with a high doping level of Na1/2Bi1/2（Sb1/2Nb1/2）O3 exhibit obvious frequency dependence between room temperature and tf.

关 键 词：钛酸铋钠 无铅压电陶瓷 介电性能 弛豫特性 

分 类 号：TM282[一般工业技术—材料科学与工程]