针对磁性复合结构的透射电镜表征新技术与磁畴三维立体结构的高分辨研究

项目名称： 针对磁性复合结构的透射电镜表征新技术与磁畴三维立体结构的高分辨研究

项目编号： No.11274066

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 车仁超

作者单位： 复旦大学

项目金额： 90万元

中文摘要： 磁性复合结构，如纳米核壳材料在药物附载等领域具有重要应用。但由于透射电镜的物镜会产生约2T的强磁场，磁性材料的高分辨观察很困难，被单畴化的样品更是缺失了原始的磁畴结构信息。本课题旨在探索发展一套先进的、基于透射电镜的针对磁性复合结构的表征方法与技术，既能高倍率观察磁材料结构，也能准确分析其真实磁畴状态：改变传统观察模式为关闭物镜的自由透镜模式，重组各级透镜参数并研究该成像条件下的电子光学，以得到高质量/高倍数的洛伦兹显微像；研究磁材料的超显微结构，包括：利用三维重构技术与洛伦兹成像，研究磁畴的三维立体形态；利用电子全息技术，定量分析各类磁性复合结构的剩余磁化强度等磁性质；结合新颖的磁圆二向色性和大角度会聚束电子衍射，定量分析核、界面、壳、膜面等区域的过渡族元素的电子自旋状态、并定性分析布洛赫壁、尼尔壁等磁畴壁结构；在电镜中原位加磁场，研究畴壁对外场的响应规律；原位通入反应气，研究生长机理。

中文关键词： 洛伦兹透射电镜；磁畴；斯格明子；电子光学；磁核壳结构

英文摘要： Magnetic composite structures, such as nano-magnetic core/shell materials, have important applications in drug delivery fields. However, due to a strong magnetic filed (2 Tesla) generated from the objective lens of transmission electron microscope (TEM), it is very difficult to observe magnetic materials with high-resolution, moreover, the saturated specimen with single-domain structure lost the initial magnetic structure information. This project aims at establishing a set of advanced and efficient TEM method and technique for the characterization of magnetic composite structures. Both high-resolution observing magnetic materials and accuratly analyzing the initial magnetic states of magnetic specimens can be achieved. Transforming from the conventional TEM observing mode into free-lens-controllable mode, to avoid of the influences of objective lens, to re-combine each lens data and to study the electron optics under this imaging condition, hig-resolution/high-quality Lorentz images could be obtained. By 3D tomography reconstruction technique and Lorentz imaging, the 3D morphology of magnetic domain will be investigated.By electron holography techniques, the residual magnetic flux density (Br) and other megnetic properties of many types of mmagnetic composite structures could be quantitatively studied. Combinin

英文关键词： Lorentz transmission electron microscope；magnetic domain；Skyrmion；electron optics；magnetic core@shell structure