纳米双相交换耦合磁体的研究进展

Research progress on exchange-coupled magnets

纳米软硬磁双相交换耦合磁体结合了软磁材料高饱和磁化强度和硬磁材料高矫顽力的优势,磁能积得到明显提高,有望成为大规模应用的新一代永磁材料。介绍了纳米双相耦合磁体的几种假设模型及理论,几种实验室制备方法(包括自下而上法、溅射法、表面活性剂辅助球磨法、高温高压成型、等离子烧结等)及目前取得的成果,以及验证软硬磁双相交换耦合作用的常用表征手段(包括退磁曲线及不可逆磁化率的分析、能谱仪、电子能量损失谱、三维原子探针等),并对交换耦合磁体的研究与应用进行了展望。

Exchange-coupled nanomagnets combine advantages of both hard magnetic phase （high coercivity） and soft magnetic phase （high saturation magnetization）, which give rise to enhancement of energy product. Therefore hard/soft nanomagnets are promisingly regarded as the new generation permanent magnetic materials. This paper reviews fundamental theory and models, some preparation methods （including bottom-up approach, sputtering method, surfactant-assisted ball milling, high-pressure warm compaction, spark plasma sintering） and achievements, and common characterization methods （including demagnetization curve and irreversible magnetic susceptibility, energy dispersive spectroscopy, electron energy loss spectroscopy, 3D atom probe）. Based on the progress, potential developments of exchange-coupled magnets are proposed.