纳米复合钕铁硼(Nd-Fe-B)永磁材料由于其理论预言的优异磁能积和较低的稀土含量而有望成为新一代永磁材料的主要发展方向。近年来提出了一种通过Nd-Fe-B块体非晶合金晶化处理直接获得全密度块体纳米复合永磁体的新方法，但由于晶化过程中软硬磁相晶粒的异常长大及其分布的不均匀性导致该方法获得纳米复合磁体的交换耦合效应部分失效，其剩磁和磁能积欠佳。本项目基于Nd-Fe-B块体非晶合金的非平衡相变原理，研究在磁场热激励下Nd-Fe-B块体非晶发生的结构弛豫演变及后续的晶化动力学过程，采用密度泛函理论分析磁场和温度共同作用下非晶合金中原子输运进程和化学短程序畴的形成，阐明结构弛豫所形成的有序原子团簇结构对结晶过程的形核方式及块体纳米复合永磁体硬磁性能的调控机制，并从微磁学角度揭示三维纳米复合结构中软硬磁相局域交换耦合的形成机理，为开发全密度高性能块体纳米复合永磁体的制备及理论研究提供依据。

Nanocomposite rare earth magnet is hopefully to be a candidate for a new generation of permanent magnet due to its excellent theoretical permanent magnetic property and low content of rare earth. Recently, fully dense bulk nanocomposite rare-earth magnets have been successfully obtained directly through a devitrification annealing process of amorphous precursors. However, the maximum BH product and remanent flux density are not so good due to coarsening of soft and hard magnetic phase grain and its inhomogeneous distribution. Depending on the principle of nonequilibrium phase transition, the evolution of the structural relaxation and subsequent crystallization kinetics under magnetic field heat treatment is investigated in this work. The effect of the magnetic field and temperature on the atomic transport processes and the formation of chemical short domains in amorphous alloy is analyzed by using density functional theory. The influence of ordered atomic cluster structure caused by the structural relaxation on crystallization nucleation process and hard magnetic properties of bulk nanocomposite permanent magnetis is clarified. The mechanism of local exchange coupling between soft and hard magnetic phase in bulk nanocomposite permanent magnets is revealed. It will provide the basis for the development of full-density and high-performance bulk nanocomposite permanent magnets.