磁改性碳纳米管复合材料的原位电子显微学与微波吸收特性研究

项目名称： 磁改性碳纳米管复合材料的原位电子显微学与微波吸收特性研究

项目编号： No.50872145

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 无线电电子学、电信技术

项目作者： 车仁超

作者单位： 复旦大学

项目金额： 36万元

中文摘要： 共发表文章19篇，其中SCI收录16篇。主要结果如下：利用洛伦兹原位电子显微学研究了纳米磁性材料的磁畴壁结构、及其对外加原位磁场的响应，并建立了与材料吸波特性的关联；合成并利用透射电镜研究了铁填充碳管的微磁畴结构、四氧化三铁/氧化钛的核壳结构与静态磁特性及其吸波特性；合成并利用透射电镜研究了中空钛酸钡纳米碗、中空氧化铜立方体、氧化铁/介孔氧化硅、超细硫化铋、微米碳酸钙、介孔硫化钼、纳米硫化锌、钆铁磷氧等多种材料的结构与吸波特性。纳米铁镍薄膜的布洛赫畴壁可以在洛伦兹透射电镜模式下被探测到磁圆二向色性信号，而尼尔壁则没有；电子全息结果证实：在碳纳米管限域空间内，磁性铁单晶纳米线将劈裂为多个单畴；上述多种纳米无机结构的研究表明，介电损耗与磁损耗的复合将有效增强微波吸收能力。氧化铜微米笼结构在8GHz频率处的微波衰减可达-8dB；氧化铁复合结构在7GHz的的微波衰减可达-24dB，以上结果分别发表在Small（1篇）, JMC（3篇）, Nanoscale等国际刊物上。不仅圆满完成了本课题的研究内容，而且产出了多篇高水平论文。

中文关键词： 微波吸收；透射电子显微学；纳米结构；核壳结构;磁畴。

英文摘要： 19 papers are generated from this project, 16 of them are cited by SCI. The main results include: via Lorentz in situ transmission electron microscopy (TEM), the association between magnetic domain wall structure of nano-magnetic materials and its response to the applied field and microwave absorption properties are established. By advanced TEM techniques and controablle synthesis, the static magnetic perperty of Fe/CNTs domains and Fe3O4/TiO2 core/shell are studied. By the same techniques, the structure and microwave absorption property of hollow BaTiO3 nanotorus, hollow CuO cubic cages, Fe3O4/meso-SiO2, ultrafine-Bi2S3, CaCo3, meso-MoS2, nano-ZnS, GeFePO oxide are comprehensively investigated. Electron magnetic circular dichrism (EMCD) signal can be detected from the Bloch wall of nano-Permalloy film, instead of Neel wall. By electron holography, within the limited volume of CNTs, the single-crystal magnetic iron nanowire was splitted into multi-domains. Briefly, combination of dielectric and magnetic lossy could effectively improve the microwave absorption ability of composites. At 8 GHz, CuO cages has a absorption of 8 dB, while Fe3O4 composites has a strong absorption of 24 dB at 7 GHz. The above results were published at international journals such as Small(1 paper), JMC (3 papers), and Nanoscale (1 paper).We not only finished the targeted content of this project, but also generate many high-level publications.

英文关键词： microwave absorption;transmission electron microscopy;nanostructure;core/shell structure;magnetic domain.