摘要
掺杂是改善Ba0.7Sr0.3TiO3(BST)性能的重要方法之一,而认识其热演变过程和相组成有助于制备性能优异的BST.本文选取分析纯醋酸镍Ni(Ac)2、醋酸钡Ba(Ac)2、醋酸锶Sr(Ac)2、和化学纯钛酸丁酯Ti(OC4H9)4为主要原料,冰醋酸HAc为溶剂和酸度调节剂、乙二醇-甲醚C3H8O2为摩尔浓度调节剂,采用溶胶-凝胶法按组分为Ba0.7Sr0.3(Ti1-xNix)O3(x=0,0.05,0.10,0.20和0.30)的化学计量比在醋酸溶液体系中制备了未掺杂和掺Ni的钛酸锶钡的凝胶和粉末.运用DSC研究了Ni的掺入对BST热演变过程影响.采用慢扫描和快扫描XRD技术分析了Ni掺杂对相组成、晶面间距和晶粒尺寸的影响.Ni掺杂强烈影响BST体系的热演变过程特别是晶化过程,由未掺杂BST体系的双相变过程逐渐变成单相变过程,加快了反应速率.经750℃晶化退火0.5h的Ni掺杂BST体系,得到单一的纯BST相不是单相变过程而是双相变过程.XRD分析结果表明,在相同热经历状况下,Ni掺杂BST体系晶化反应充分完全,BST相结晶性良好,当Ni掺入量到0.05时得单一的BST相;随Ni掺入量进一步增多,BST体系中(Ba,Sr)CO3相的含量增多.BST晶体(110)晶面间距d随Ni的掺入增大而增大,且晶粒尺寸逐渐减小.
Abstract： Doping method is a good and effective technique to modify the dielectric properties of barium strontium titanate （BST） ferroelectric material system. The highlight in its pyrolysis evolution and phase constitutes is in favor of preparing a high quality of production. In this work, Ba0.7 Sr0. 3 （TiO3 Ni）03 （x= 0, 0.05, 0. 10, 0.20 and 0.30） precursor solutions were confected by using analytical purity of barium acetate, strontium acetate and nickel acetate and chemical purity of Ti（OC4 H9 ）4 as the starting materials, 2-methoxyethanol and acetic acid as solvent and acety- lacetone as stability solvent. Gels and powders of Ba0 7 Sr0.3 （Ti3 , Mnr ）O3 were prepared by sol-gel technique. DSC was used to investigate the effect of Ni-doping on the pyrolysis evolution, and the slow-and fast-scanning XRD tech- niques were used to study the effect of doping behavior on the constitutes and plane spacing of （110） and grain size of BST system. These results indicated that Ni-doping led to a remarkable change of the phase constitutes and the crystallizing process of BST from a double phase-transformation of the sample without dopant into a single phase- transformation of one with increase in amount of Ni-dopant. At the same time, it also caused a rapid increase in the reaction rate of crystallizing. The crystallizing process of the Ni-doped BST powders proceeded more completely and the erystallinity of BST phase became better during the same thermal history. And nano-scaled single phase BST can be obtained when the level of Ni dopant is 0.05 with a proper fabrication process determined., the sample is annealed at 750℃ for 0. 5 h to crystallize into perovskite phase. With further increasing of the Ni dopant, the amount of （Ba, Sr）CO3 monitored by XRD increased. It is of interest that when single phase-transformation with high reaction rate during crystallizing occurs in, a single phase BST production could not be obtained, and contrarily, double phase- transformation with closed reactio
出处
《南京大学学报（自然科学版）》
CAS
CSCD
北大核心
2009年第2期203-210,共8页
Journal of Nanjing University（Natural Science）
