铁酸铋基高温无铅复合铁电陶瓷的结构及电学性质的调控和优化

铁电材料在换能器、驱动器等电子器件中具有广泛的应用，是一类重要的功能材料。近年来，由于环保意识的增强，无铅铁电材料的研究逐渐成为主流，同时，为了满足电子器件在高温环境中稳定工作的迫切需求，高温铁电材料也得到了重视和关注。本项目拟选取具有高居里温度的BiFeO3基无铅铁电陶瓷为研究对象，通过第二相复合和淬火的制备方式，系统研究其相结构、微观形貌、电学性能及其高温稳定性，研究其铁电畴形貌、翻转动力学、畴壁导电性等在电场、温度作用下的演变规律，特别是两相界面处铁电基体的铁电畴结构，从而揭示BiFeO3基复合铁电陶瓷的相结构、铁电畴结构与电学性质及其高温稳定性的依赖关系，理解调控和优化其结构、电学性能的物理机制，为设计和制备新型、高性能的高温无铅复合铁电陶瓷提供可靠的实验和理论依据。

Ferroelectric material is one of the most important functional materials, which has widely application in transducers and actuators. Recently, lead-free ferroelectric materials have become a hot topic due to the enhanced environmental concern. And the ferroelectric materials with high Curie temperature also have attracted more attention to meet the emerging requirements for the electronic devices to work at high temperature. In this proposal, the BiFeO3-based ferroelectric ceramics with high Curie temperature will be designed and fabricated by composite and quenching approaches. Then their phase structure, micromorphology, electrical properties and the thermal stability will be systematically investigated. More importantly, the local phase structure, ferroelectric domain, domain switching and conductivity of domain wall under the electric field and temperature will also be investigated. Therefore, the relationship between the phase structure, ferroelectric domain, electrical properties and thermal stability of BiFeO3-based composite ferroelectric ceramics will be proposed and the physical mechanism of improved properties for BiFeO3-based ceramics will also be understood, which may provide reliable experimental and theoretical clues to design and fabricate novel lead-free ferroelectric composite ceramics with high performances at high temeprature.