文档介绍：哈尔滨理工大学工学硕士学位论文改进的溶胶凝胶法制备铌酸锶钡/钛酸锶钡复相陶瓷研究摘要四方钨青铜结构的铌酸锶钡(SrxBa卜xNb206,<X<,简写为SBN) 和钙钛矿结构的钛酸锶钡(,简写为BST)具有优良的电学性能, 是实验研究和应用开发的热点。为了发掘两类材料更优异的性能进而探索其实际应用的可能性,人们开始研究SBN和SBT复合陶瓷的制备和介电性能。本文采用改进的溶胶凝胶法制备SBN和BST两相共存的复相陶瓷,简称BSTN,系统研究了其制备方法和及制备过程中各影响因素。同时分析了复相陶瓷体系中不同Sr/Ba比和Nb/Ti比对体系结构及介电性能的影响。7采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)等方法系统研究了BSTN的结构,。通过阻抗测试仪及LCR数字电桥分析了BSTN复相陶瓷的介频特性及介温特性。本论文的研究表明:(1)与传统复相陶瓷的制备方法固相法相比,改进的溶胶凝胶法有利于两相的良好固溶,同时降低烧结温度并抑制晶粒的异常生长;(2)通过对前聚体干凝胶的热分析得到其最佳的预烧温度为800℃, 并结合现有烧结炉制定出烧结过程中的升温曲线;(3)分析了烧结温度和烧结时间对复相陶制备的影响,得到:钙钛矿相BST的形成温度低于钨青铜相SBN,确定实验采用烧结温度1250℃烧结3h;(4)~ 之间钙钛矿相和钨青铜相可以良好的固溶在复相体系中。随着X值的增加复相陶瓷室温下的介电常数逐渐减小,而介电损耗逐渐增加。所以当体系 Sr/Ba比为3/7时,介电常数较大的同时介电损耗较小,且居里温度在室温范围,对提高介电器件的性能有着重要的意义;(5)固定Sr/Ba比为3/7,··()Ti02"yNb205的相组成和微观结构与 Nb/Ti比的关系。随着体系中Nb5+含量的增加,其居里温度不断升高,介电常数和介电损耗都减小,当y=,可以认为复相陶瓷的介电性能得到了很好的改善。关键词改进的溶胶凝胶法;复相陶瓷;介电器件;钨青铜相;钙钛矿相-I. 哈尔滨理工大学工学硕士学位论文 Characterization ofModified Derived xSrO·(1一x)BaO·yNbeOs·(1一y)posite Ceramics Abstract Strontium barium niobate with tetragonal tungsten bronze structure and barium strontium titanate with perovskite structure have attracted lots of attention due to their outstanding dielectrical properties and potential SBN with defect that was difficult sintered to a high density and can abnormal grain posite material with good dielectric properties,mechanical properties may be obtained by acomposite of BST and thispaper(1-x)BaO‘xSrO。(1·y)Ti02‘yNb20s(BSTN inshort) withcoexistence of theperovskite andtungsten bronze phases were essfully prepared by amodified sol—gelmethod,and the formation mechanism of posite ceramics was investigated effectofdifferent Sr/Baratio and Ni/Ti ratio tothestructure and properties ofthematerials were also studied. Some instruments were chose included X-ray diffraction(XRD),scanning electron microscope(SEM),impedance instrument and alsoLCR digital bridge. Following re