新型层状异质纳米永磁材料的构筑和性能研究

本项目针对永磁材料发展面临的饱和磁化强度与矫顽力的倒置关系这个关键科学问题，开展新型层状异质纳米永磁材料的构筑和性能研究。拟选择SmCo、NdFeB、(Nd,Dy)FeB永磁材料和FeCo软磁材料为结构组元，采用高压热压缩变形技术构筑四类SmCo基块体、层状、异质纳米结构。研究高压热压缩变形下层状结构的可控构筑；研究层状结构中硬磁纳米晶的取向生长及其与变形条件的关联，研究极端变形条件对软磁相晶粒尺寸（~10 nm）和硬磁相晶体取向（沿易磁化方向）的同时控制；研究层状结构的构筑组元和构筑方式对磁性的调控。建立块体层状异质纳米材料的变形工艺－微结构－磁性的关系。探索复杂层状异质纳米结构的构筑在解决磁化强度与矫顽力倒置关系方面的作用。本项目的构想是在我们长期研究工作基础上产生的，具有鲜明的开创性特征和研究特色。它的完成将推动永磁材料学科前沿取得突破，发展永磁材料制备的新原理和新技术。

In this project, to overcome the trade-off between saturation magnetization and coercivity that is a key scientific problem hindering the development of permanent-magnetic materials, the design and architecture of novel layered hybrid nanostructured permanent magnets will be carried out and their properties will be studied. SmCo、NdFeB and (Nd,Dy)FeB hard-magnetic materials and FeCo soft-magnetic material will be chosen as constituents to build four types of SmCo-based bulk, layered, hybrid nanostructures, through High-Pressure Thermal Compression (HPTC) approach. The controllable architecture of layered structure will be studied. The preferential growth of hard-magnetic nanograins under HPTC in the designed layered structure and its relationship with deformation conditions will be investigated, and a simultaneous control of the alignment of hard-magnetic nanograins along their easy magnetization axes and the grain size (~ 10 nm) of soft-magnetic phase will be studied. The magnetic properties will be tuned through varying constituent components and their arrangements in the materials. The "deformation processing - microstructure - magnetic properties" relationship for designed layered hybrid materials will be established. The role of designed complex layered hybrid nanostructures in overcoming the trade-off between the saturation magnetization and coercivity will be explored. This project is conceived based on our long-term research works and has distinctive originality, its completion will lead to a breakthrough for the frontiers of permanent magnetic material subject and produce new principles and technologies for fabricating hard-magnetic materials.