巨介电常数材料微波介电性能的评价

项目名称： 巨介电常数材料微波介电性能的评价

项目编号： No.50802087

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 电工技术

项目作者： 李雷

作者单位： 浙江大学

项目金额： 20万元

中文摘要： 发展用于精确评价巨介电常数材料微波介电性能的改进型金属谐振腔法，针对试样有、无磁性两种情况分别发展和完善相应的测试方法，并建立可变温评价系统；以CaCu3Ti4O12、Ba(Fe1/2Nb1/2)O3 及CoFe2O4/Sr0.5Ba0.5Nb2O6 复相陶瓷这三种典型的巨介电常数材料为对象，验证改进型金属谐振腔法的可行性，研究微波介电性能对频率、温度的敏感性及微结构对微波介电性能的影响，并结合较低频率下的介电性能，探索各种极化机制在不同频率下的响应及低频下巨介电效应的起源。本研究的开展有望实现包括巨介电常数材料在内的高损耗材料微波介电性能的高精度测试，从而将人们对巨介电常数材料介电性能的认识拓展至微波频段。这有助于从不同的角度加深对巨介电效应物理本质的理解，并为巨介电常数材料可能的微波应用奠定基础。

中文关键词： 改进型金属谐振腔法；巨介电常数材料；微波介电性能

英文摘要： The modified metal resonant cavity method is developed to accurately evaluate the microwave dielectric properties of giant permittivity materials. The present method is suitable for magnetic and non-magnetic giant permittivity materials, and the temperature-tunable measuring system is established. The typical giant permittivity materials of CaCu3Ti4O12, Ba(Fe1/2Nb1/2)O3 and CoFe2O4/Sr0.5Ba0.5Nb2O6 composite are used to prove the feasibility of the modified metal resonant cavity method. The dependence of their microwave dielectric properties on the frequency, temperature and microstructure is investigated, and the response of the polarization mechanisms at varying frequencies and the origin of the giant permittivity effect are discussed combining with the dielectric properties at low frequency. Through the present research, the accurate measurement for the microwave dielectric properties of the giant permittivy and other high-loss materials is expected. This will help understand the physical nature of the giant permittivity effect from a new point of view and lay the foundation for the possible microwave applications of the giant permittivity materials.

英文关键词： Modified metal resonant cavity method; Giant permittivity materials; Microwave dielectric properties