(Sr_(1-3x/2)La_x)TiO_3(x=0.2～0.5)陶瓷的显微组织结构及微波介电性能研究  

Crystal Microstructure and Microwave Dielectric Properties of (Sr_(1-3x/2)La_x) TiO_3 (x = 0.2-0.5) Ceramics

作　　者：孙明辉 徐越 王雪婷 李世信 胡海旭 于迎波 王雪[1] SUN Ming-hui;XU Yue;WANG Xue-ting;LI Shi-xin;HU Hai-xu;YU Ying-bo;WANG Xue(School of Materials Science and Engineering,Qilu University of Technology(Shandong Academy of Sciences),Jinan 250353,China;School of Electrical Engineering and Automation,Qilu University of Technology(Shandong Academy of Sciences),Jinan 250353,China)

机构地区：[1]齐鲁工业大学(山东省科学院)材料科学与工程学院,济南250353 [2]齐鲁工业大学(山东省科学院)电气工程与自动化学院,济南250353

出　　处：《齐鲁工业大学学报》2018年第6期7-12,共6页Journal of Qilu University of Technology

基　　金：国家自然科学基金(61805125);2018年全国大学生创新训练计划项目(201810431021);山东省自然科学基金(ZR2018LE003)

摘　　要：通过固相反应法制备(Sr_(1-3x/2)La_x) TiO_3(x=0.2～0.5)复合体系微波介质陶瓷,并对其显微组织结构、晶体结构及微波介电性能进行研究。XRD结果表明(Sr_(1-3x/2)La_x) TiO_3系微波介质陶瓷为六方晶系钙钛矿结构。显微组织结构表明陶瓷的晶粒尺寸随着烧结温度的提高而增大,气孔呈现先减少后增多的趋势,并且陶瓷的晶界在高温过烧时出现晶界明显扩张的现象。介电性能结果表明陶瓷的密度、介电常数和品质因数均随烧结温度的提高先增大后减小,谐振频率温度系数和热膨胀系数则呈现与之相反的变化趋势,同时除密度在1 450℃下取得最值外其余各检测值均在1500℃下取得最值。在烧结温度为1 500℃时,(Sr_(0.55)La_(0.3)) TiO_3陶瓷具有致密的结构、清晰明显的晶界、气孔数量较少,平均晶粒尺寸为14.24μm,此时(Sr_(0.55)La_(0.3)) TiO_3陶瓷具有优良的介电性能:Q×f=8960.43GHz,ε_r=60.54,τ_f=16 ppm/℃。The microwave dielectric ceramics of(Sr1-3x/2Lax)TiO3(x=0.2-0.5)were prepared by solid state reaction,and their microstructure,crystal structure and microwave dielectric properties were investigated.XRD shows that the(Sr1-3x/2Lax)TiO3 has a hexagonal perovskite-like structure.The microstructure shows that the increase of sintering temperature causes an increase in the grain size,and the amount of pores reduces first and then increases.Moreover,the grain boundary of ceramics expands significantly when overburnt.The results of dielectric properties show that the density,dielectric constant and quality factor increase first then decrease with the increasing ofsintering temperature.The temperature coefficient of resonator frequency and thermal expansion coefficient show opposite variation tendency.Except for the density which obtains maximum value at 1 450℃,the other detection values obtain their highest point at 1 500℃.At sintering temperature 1 500℃,the(Sr0.55La0.3)TiO3 ceramic has a dense structure,clear and distinct grain boundaries,and few pores.The average grain size is 14.24μm,and the(Sr0.55La0.3)TiO3 ceramic has excellent dielectric properties:Q×f=8960.43 GHz,εr=60.54,τf=16 ppm/℃.

关 键 词：微波介质陶瓷 钙钛矿结构 微波介电性能 (Sr1-3x/2Lax)TiO3 

分 类 号：TQ174.79[化学工程—陶瓷工业]