铁系金属/氧化物低维磁结构的可控制备与单体磁电特性电镜原位研究

Metal/oxide magnetic structures of well-controlled shape and size with low dimensions are recently one of hottest research topics in material science and condensed matter physics, which is because of not only their unique and novel physical properties from a fundamental point of view but also the future industrial demands to systematically reduce the size of spin and tunneling devices, continuously increase the density of magnetic recording, and precisely tailor the performance of permanent magnetic materials. This project is aimed to kick-start a research of controlled preparation of low-dimensional magnetic metal/transition metal oxide architectures by methods of chemical synthesis and jointed techniques of high-vacuum sputtering and focused-ion beam milling. Their morphologies, crystal structures, chemistry and electronic states will be comprehensively characterized at the nanoscale, which lead to achieve a high-quality and fully controllable preparation of various low-dimensional magnetic metal/transition metal oxide architectures. Their intrinsic and technical magnetic properties will be tested, which includes a deep investigation of their atomic magnetic moments vs. temperature and atomic magnetic moments vs. external field. The physical mechanisms and principles how the electric, magnetic, and magneto-transparent behaviors of individual low-dimensional magnetic metal/transition metal oxide architectures are influenced by their sizes, shapes, morphologies, structures, basic components, inner interfaces and defects will be studied at the nanoscale and atomic scale by means of dedicated electron microscope in-situ nanomanipulators developed by own which directly provide a simultaneous and dynamic monitoring of the whole experimental processes. This project is believed to contribute not only diverse smart functional 3D building blocks of low-dimensional magnetic structures, but also useful experimental and theoretical knowledge for developing spintronic devices, high-density magnetic recording media, high-performance permanent magnetic materials, flux amplifiers of magnetic resonance imaging.

形状、大小可控的低维金属/氧化物磁结构是最近几年来材料科学和凝聚态物理研究的热点之一，原因不仅在于它们呈现出的新奇物理性质所具有的重要基础研究价值，而且是被认为实现未来自旋电子器件进一步微型化、磁记录密度进一步提高、硬磁材料磁性精确调控等的实际应用需要。本项目拟在通过化学合成和真空溅射结合聚焦离子束电镜刻蚀两类方法制备形状、大小可控的铁系金属/氧化物低维磁结构，通过对其形貌、结构、元素成份和电子态的测量，研究掌握它们的精确可控的制备工艺；通过宏观和微观磁性的系统测量，掌握它们的内禀、技术磁性，以及原子磁矩随温度和磁场的变化；利用课题组开发的电镜原位磁输运测量仪器进行实时、动态、图像化研究单个低维磁结构的磁电性质如何受其尺寸、形貌、结构、种类和界面的影响,在纳米甚至原子尺度上深入认识和揭示低维磁结构的磁相互作用机制和磁性调控机理，为该类材料的开发和应用提供依据。

形状、大小可控的低维金属/氧化物磁结构是最近几年来材料科学和凝聚态物理研究的热点之一，原因不仅在于它们呈现出的新奇物理性质所具有的重要基础研究价值，而且是被认为实现未来自旋电子器件进一步微型化、磁记录密度进一步提高、硬磁材料磁性精确调控等的实际应用需要。本项目拟在通过化学合成和真空溅射结合聚焦离子束电镜刻蚀两类方法制备形状、大小可控的铁系金属/氧化物低维磁结构，通过对其形貌、结构、元素成份和电子态的测量，研究掌握它们的精确可控的制备工艺；通过宏观和微观磁性的系统测量，掌握它们的内禀、技术磁性，以及原子磁矩随温度和磁场的变化；利用课题组开发的电镜原位磁输运测量仪器进行实时、动态、图像化研究单个低维磁结构的磁电性质如何受其尺寸、形貌、结构、种类和界面的影响。项目按计划制备出了几种能够用于研究铁磁-非铁磁相互作用的低维铁系金属/氧化物磁性结构理想模型样品，掌握它们的制备工艺；研究它们的宏观磁性和单体微观磁电特性受立体几何形状、尺寸、界面结构、晶体微结构和化学成份的影响，探索、阐明它们在纳米甚至原子尺度上的磁相互作用机制和磁性调控机理。在项目执行过程中较为严格地按照研究计划开展了研究工作，除此之外，我们深入研究了低维铁系金属/氧化物磁性结构在其他领域的扩展应用，获得了一些具有原创性重要意义的研究成果，基本上完成了全部项目计划，并在国际重要期刊上发表了SCI一区论文10篇，二区论文4篇，中文核心期刊2篇，会议论文80余篇，获批专利20项，获邀做国内外学术会议特邀报告44次。项目研究成果实现了在纳米甚至原子尺度上深入认识和揭示低维磁结构的磁相互作用机制和磁性调控机理，为该类材料的开发和应用提供依据。