溶胶凝胶法制备掺铅钛酸钡纳米晶及其结构相变  

Structure Phase Transition of Nanocrystalline Barium Titanate Doped with Lead Prepared by Sol-Gel Methods

作　　者：范仰才[1] 蒋力立[1] 唐新桂 周歧发[2] 张进修[2] 

机构地区：[1]广东工业大学应用物理系,广州510090 [2]中山大学物理系,广州510275

出　　处：《无机材料学报》2000年第5期797-801,共5页Journal of Inorganic Materials

基　　金：广东省自然科学基金!(980370)

摘　　要：采用溶胶－凝胶工艺制备了不同晶粒大小的、掺铅（５ｍｏｌ％）钛酸钡（ＢＰＴ）纳米晶．用ＴＥＭ、ＸＲＤ和ＤＳＣ研究了ＢＰＴ样品的晶粒大小、结构及其相变特性．结果表明，纳米晶ＢＰＴ随着晶粒尺寸的减小，由铁电四方相向顺电立方相过度，并且相变变得弥散．其顺电－铁电相变随着晶粒尺寸的减小而消失．另一方面，随着晶粒尺寸的增加，其铁电四方－铁电正交相交消失，即抑制了其正交相的形成．Nanocrystalline (Ba,Pb)TiO3 (5 mol% Pb) with various grain sizes were prepared by a sol-gel process. The gain size, structure and phase properties of nanocrystalline BPT were studied by TEM, XRD and DSC. The results show that the structure phase transition is from ferroelectric tetragonal to paraelectric cubic phase and becomes more diffusive with decreasing particle size. On the other hand, the ferroelectric orthorhombic to ferroelectric tetragonal phase transition disappears with increasing particle size, it means that the formation of the unwanted orthorhombic phase of BaTiO3 is inhibited.

关 键 词：溶胶-凝胶法 纳米晶 结构相变 铅钛酸钡 铁电体 

分 类 号：TM221.014[一般工业技术—材料科学与工程] TQ132.35[电气工程—电工理论与新技术]