BiFeO3不同格位缺陷的特征及其对电磁性能的影响

项目名称： BiFeO3不同格位缺陷的特征及其对电磁性能的影响

项目编号： No.11305142

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 代海洋

作者单位： 郑州轻工业学院

项目金额： 20万元

中文摘要： 钙钛矿结构化合物BiFeO3是目前唯一在室温下同时具有铁电性、磁性和磁电耦合效应的单相多铁材料，该材料不仅具有潜在的应用前景，而且其丰富的物理内涵更是具有极其重要的理论研究价值，成为近年来凝聚态物理、材料科学领域研究的热点内容之一。本课题拟在前期工作的基础上，（1）通过制备及后处理工艺的控制、离子替代/掺杂在块材体系样品的A位、B位引入缺陷，采用正电子湮没等技术研究不同晶格位置缺陷种类、大小、浓度分布等对体系电磁性能的影响规律；（2）采用正电子湮没等技术探究BiFeO3/La0.7Sr0.3MnO3等多层膜界面处缺陷种类、大小、浓度分布等对体系电磁性能的影响规律；（3）结合第一性原理模拟计算，阐明材料的缺陷对体系电磁性能影响的机理。该研究将为BiFeO3类多铁材料基本物理机制的理解提供基础实验资料，同时为该材料在信息存储、电子元器件方面的开发应用提供基础研究支持。

中文关键词： BiFeO3；电磁性能；微结构；正电子湮灭；缺陷特征

英文摘要： As a single phase multiferroic materials, BiFeO3 exhibits simultaneous presence of ferroelectric and magnetic properties in the same phase with electromagnetic coupling between them. In the past few years, great attentions have been paid to BiFeO3,because they not only have a whole range of new potential applications, but also have interesting and fascinating fundamental physics. In this proposal,we will study on the following based on pre-preparation of BiFeO3 multiferroics materials.(1)The defect evolution of BiFeO3 materials induced by prepared technics,ions deoping and heat treatment,and their influences on the ferroelectric and magnetism properties;(2)To explore the effects of defect characters at the interface on the ferroelectric and magnetism properties of BiFeO3/La0.7Sr0.3MnO3 multilayers;(3)The micro-mechanism of defect characters on the ferroelectric and magnetism properties of BiFeO3 system are studied by simulation using first-principle and experimental results. This research can provide theoretical and experimental basis for the mechanism study of multiferroics and the application of information storage and electronic devices.

英文关键词： BiFeO3；Electric and magnetic properties；Microstructure；Positron annihilation；Defects character