《微波介质陶瓷改性研究》-毕业论文（设计）.doc

Ba6-3xLa8+2xTi18O54(x=2/3)微波介质陶瓷Zr4+取代的改性研究 摘　　要 Ba6-3xLa8+2xTi18O54固溶体具有高介电常数、低损耗和近零温度系数，因此成为制备微波介质谐振器、滤波器的关键材料。关键词：Ba6-3xLa8+2xTi18O54 Zr4+取代 微波介电性能 烧结性能 实验采用高温固相反应法合成Ba6-3xLa8+2xTi18O54并利用Zr4+取代Ba6?3xLa8+2xTi18O 关键词：Ba6-3xLa8+2xTi18O54 Zr4+取代 微波介电性能 烧结性能 对于复合体系采用XRD、SEM、EDS、微波介电测试等分析方法，研究了复合体系微波介质陶瓷材料在1300～1600 ℃下的烧结工艺、相组成、微观结构和微波介电性能。研究表明：复合体系在整个z组成范围内除了z=0.1，都可以形成致密的陶瓷。并且z=0.1以后出现了第二相Ba2ZrO4。介电常数、品质因数与谐振频率温度系数均随着z的增大而不同程度的减小。当z=0.05时，得到最佳性能：εr=86.83，Q×f=5875 GHz，τf =81.99×10-6/°C。 Effects of Zr4+ substitution on microwave dielectric properties of Ba6-3xLa8+2xTi18O54(x=2/3) ceramics Abstract Ba6-3xLa8+2xTi18O54 solid solutions with a high dielectric constant, low dissipation and near-zero temperature coefficient, thus becoming the key materials to preparat microwave dielectric resonator, filter materials. Experiment using high-temperature solid state reaction synthesis of Ba6-3xLa8+2xTi18O54 and use Zr4+ instead of Ba6 ? 3xLa8+2xTi18O54 (x=2/3) ceramic b-Ti4+,expect to improve the quality factor and temperature stability of this system ceramic on the basis of keeping high dielectric constant by Zr4+ substitution. For a composite system using XRD, SEM, EDS and microwave dielectric test analysis method,The complex system of microwave dielectric ceramics , sintering process , phase composition, microstructure and microwave dielectric properties is studied under the 1300 ～1600 ℃.The research indicates that expect z is equal to 0.1, sense ceramic can be formed within the limits of the whole z component, in the composite systems. The second phase, Ba2ZrO4 appears when z is greater than 0.1. With the enlargement of z, dielectric constant, quality factor and HYPERLINK app:ds:temperaturetemperature HYPERLINK app:ds:coefficientcoefficient HYPERLINK app:ds:ofof HYPERLINK app:ds:resonanceresonance HYPERLINK app:ds:frequencyfrequency decrease in a different extent. When z is equal to 0.05, we get the best property: εr =86.83, Q×f=5875 GHz，τf =81.99×10-6/°C.