含锆焦绿石介电体的制备与性能分析.docVIP

论文题目：含锆焦绿石介电体的制备与性能分析 专业：材料科学与工程 作 者：吕友红 签名 ＿＿＿＿ 指导老师：杜慧玲 签名 ＿＿＿＿ 摘 要 本文采用传统的电子陶瓷制备方法——固相反应法制备系列样品，研究随着二价Sr2+取代量的增加，所制的(Bi1.5Zn0.5-xSrx)(Zr1.5Nb0.5)O7(x=0,0.1,0.3,0.5)的介电材料的相组成、晶体结构、烧结特性、介电特性，进一步分析随着Sr2+取代量的变化，焦绿石陶瓷的相结构及介电性能的变化规律。实验结果表明，四个样品均形成了焦绿石单相结构，随着Sr2+取代量的增加，样品的晶胞参数增大，晶粒尺寸较小，大致为1μm左右；介电分析表明，介电常数、介电损耗对频率的依赖性随频率的增加而降低，四个样品的漏导触发温度随Sr2+取代量的增加而降低，介电常数温度系数由负温度系数向正温度系数转变。以上性能的改变，有望拓宽BZN系焦绿石的应用范围。 关键词：铋基焦绿石；A位取代；相结构；介电性能 论文类型：实验研究 Subject: Investigation on reparation and dielectric properties of pyrochlores containing zirconium Specialty: Material science and engineering Author: Lv Youhong Signature ＿＿＿＿ Instructor: Du Huiling Signature ＿＿＿＿ Abstract A series system of pyrochlore compounds (Bi1.5Zn0.5-xSrx)(Zr0.5Nb0.5)O7 (x=0, 0.1, 0.3, 0.5) have been prepared by solid reaction technique. The A position ion was partial substituted by Sr2+ respectively, and quaternary system of four samples were formed. The phase evolution, crystal structure, sintering characteristic and dielectric properties were systematically studied. The influence of Sr2+ replace quantity incorporation on the phase structure of Bi-based pyrochlore ceramics was discussed. The dependence of dielectric properties on the phase structure of series samples was analyzed further. XRD results show that four samples have formed the single cubic pyrochlore structure, with the increase of Sr2+ amount, the lattice constant increases. The grain size of series samples is small (about 1μm). According to the dielectric results, the dependence of dielectric constant and dielectric loss decreases with the increase of frequency. The leakage trigger temperatures decrease with the increase of Sr2+ amount, and the temperature coefficient of dielectric constants of four samples shift from negative to positive. All the change in Bi-based pyrochlores could widen their applications. Keywords: Bi-based pyrochlor