厘米级BiFeO3单晶的合成及其高温铁电相转变研究

项目名称： 厘米级BiFeO3单晶的合成及其高温铁电相转变研究

项目编号： No.51272204

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 魏杰

作者单位： 西安交通大学

项目金额： 70万元

中文摘要： 本项目研究着重于解决BiFeO3材料研究领域目前存在的研究难题：高质量大尺寸BiFeO3单晶(厘米级)的合成及其高温铁电相转变行为。项目申请人在前期预先研究的基础上，提出了合理可行的研究实施方案，通过突破两个关键性的技术瓶颈：（1）建立一个精确的Fe2O3-Bi2O3相图和（2）避免相转变过程中的体积变化效应引起的晶体开裂问题，从而制备出高质量大尺寸的BiFeO3单晶；同时，结合对高相纯度BiFeO3陶瓷和单晶的高温铁电相转变分析，最终确定BiFeO3的铁电相转变机制和高温顺电相的晶体结构。有理由相信，本项目必将产生一系列具有较高原创性的科研成果，同时也会极大地促进BiFeO3材料在功能器件方面的应用。

中文关键词： BiFeO3；单晶；铁电相转变；掺杂；多铁性

英文摘要： This project focuses on "Synthesis of High Quality Centimeter-size BiFeO3 Single Crystal and its High Temperature Ferroic Phase Transitions", which is still an open and unresolved question in this field. On basis of the previous research works on this topic, the applicants of this project propose a reasonable and executable plan. According to the arrangements in this plan, the applicants are going to do lots of experiments to overcome two technical difficulties in the synthesis of centimeter-size BiFeO3 single crystal, that are (1) establishment of a more accurate phase diagram of Fe2O3-Bi2O3 and (2) avoidance against crystals broken due to great changes in volume caused by phase transition near Curie temperature of BiFeO3, and finally successfully achieve centimeter-size BiFeO3 single crystal. Furthermore, they will make great efforts to study on the phase transition behavior of both pure phase BiFeO3 ceramics and high quality single crystals, and then make conclusions on the mechanism of BiFeO3 ferroic phase transitions and the crystal structure of its paraelectric phases at high temperature. It is well believed that this project will bring more creative achievements, and also accelerate the development in the practice applications of BiFeO3.

英文关键词： BiFeO3；single crystal；ferroic phase transition；dopant；multiferroic