缺陷富集型铁电晶体的可控制作及其物理性质研究

项目针对如何利用微结构缺陷调制铁电功能晶体物理性质这一难题，以铁电唯像理论（LGD）和半导体理论为指导，以典型的钛酸钡铁电单晶为研究对象，系统研究紫外辐照、热处理、应力、电场等因素对晶体材料中缺陷成核、生长、增殖、积聚等行为的影响机制。在此基础上研究掌握其微结构特征并制作缺陷富集型铁电晶体，结合铁电性能测试、压电探针技术、多普勒振动微区测试、半导体性能测试等分析方法，从铁电唯像理论和半导体带结构特征两个方面深入研究缺陷聚集结构对各种物理性质的调控机理，最终希望总结得到若干能够有效提升钙钛矿型铁电晶体性能的新途径和新规律。项目是铁电学基础研究的前沿课题，研究成果对于新型铁电器和钙钛矿结构的功能器件的设计、制作和应用具有一定的指导意义。

This present project aims at developing methods to tune and improve the ferroelectric and physical properties of ferroelectric crystals by introducing artificial microstructural defects. Barium titanate (BaTiO3, a typical prototype ferroelectric) crystals with enriched defects of various types will be created by means of UV irradiation, thermal treatment, stress and electrical fields. We will first concentrate on understanding the thermodynamic behaviors of defect formation with emphasis on nucleation, growth, multiplication, and accumulation. We will further examine the microstructural aspects of the samples and their relationship with the ferroelectric and physical properties on the basis of the ferroelectric phenomenological theory and semiconductor band theory. We hope that this study will find some new methods that can be utilized to improve the performance of perovskite ferroelectric crystals. This project is the frontier of modern ferroelectrics. Its outcome will pave ways for developing novel ferroelectric devices and electronic devices based on perovskite materials.