钛酸钡（BaTiO3）是电子陶瓷中最为重要的基础材料之一，在直流电场下，材料的电容和损耗通常都会随外加电场的增加而减小，而最终趋于稳定，这一现象称之为介电调谐，其可用于相控阵雷达的关键器件介质移相器中。本项目拟以BaTiO3基复合材料体系为研究对象，研究复合材料的界面效应与介电调谐性能之间的相互关系，建立复合材料介电调谐性能的理论模型。首先，研究0-3型、2-2型及1-3型BaTiO3基复合材料的制备工艺；其次，研究两相界面的成分、结构、形貌及应力状态，揭示强直流电场作用下两相界面处的极化响应及载流子的隧穿机理；最后，研究复合构型、第二相的类型、尺寸与形貌对复合材料的介电调谐性能的影响规律，建立介电调谐性能与复合构型、第二相的性质及形状参数之间的理论模型。

Barium titanate (BaTiO3) is one of the most important materials in electronic ceramics. Under DC electric field, the capacitance and loss of BaTiO3-based materials usually decrease with the increase of applied electric field, and finally tend to be stable. This phenomenon is called dielectric tunability, and can be used in the dielectric phase shifter which is the key components of phased array radar. In this project, BaTiO3-based composite materials are chosen as the object of study. The relationship between interfacial effects and the dielectric performances of BaTiO3-based composite materials are specifically investigated, and the theoretical model of dielectric tunability responses is established. To be detail, firstly, the 0-3, 2-2 and 1-3 type of BaTiO3 based composites are prepared. Secondly, the composition, structure, morphology and stress state of the interface between both phases are studied, and the interfacial polarization response and the tunneling mechanism of carrier under strong dc field are revealed. Finally, the effects of complex configuration, type, size and morphology of the second phase on the performance of dielectric tunability are studied. And theoretical model between the dielectric performance and complex configuration, properties and shape parameters of the second phase is established.