Understanding the Role of Element Grain Boundary Diffusion Mechanism in Nd-Fe-B Magnets
Understanding the Role of Element Grain Boundary Diffusion Mechanism in Nd-Fe-B Magnets
复制标题
了解元素晶界扩散机制在 Nd-Fe-B 磁体中的作用
DOI：
10.1002/adfm.202109529
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发表时间：
2021-11-10
影响因子：
19
通讯作者：
Zhang, Xuefeng
中科院分区：
文献类型：
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作者：
Zhao, Lizhong;He, Jiayi;Zhang, Xuefeng
多种稀土元素的晶界扩散（GBD）对永磁体的性能有较好的增强作用，但由于其相互作用复杂，其扩散行为尚不清楚。本文研究了三种稀土元素（Tb、Ce和La）对晶界扩散过程的协同作用，获得了具有1822 kA m（-1）矫顽力和-0.447% K-1热稳定性的高性能扩散Nd-Fe-B磁体。电子探针微分析和第一性原理计算证明，这种促进作用源于Ce和La的配位效应导致Tb在特定区域的扩散深度提高。这导致了tb扩散磁硬化晶粒的均匀形成，与强钉住的畴壁相关，这可以通过原位洛伦兹透射电子显微镜直接观察到，并通过微磁模拟重建。该研究揭示了元素GBD机制的作用，并为探索其他元素系统作为永磁体扩散源提供了良好的潜力。
Grain boundary diffusion (GBD) of multiple rare earths has proven effective in enhancing the performance of permanent magnets, whereas the diffusion behaviors are still unclear due to their intricate interactions. In this work, the synergistic effects of three rare earths (Tb, Ce, and La) on the grain boundaries diffusion process are investigated, achieving a high-performance diffused Nd-Fe-B magnet with the high coercivity of 1822 kA m(-1) and thermal stability of -0.447% K-1. This promotion originates from the improved diffusion depth of Tb at specific regions, induced by the coordination effects of Ce and La, as evidenced via electron probe microanalysis and the first-principles calculations. It thus results in the uniform formation of Tb-diffused magnetic harden grains, associated with the strongly pinned domain walls, which is further observed directly by in situ Lorentz transmission electron microscopy and reconstructed by micromagnetic simulations. The study provides insight into the role of element GBD mechanism and has promising potential to explore other element systems as diffusion sources for permanent magnets.