A Novel Strategy for the Fabrication of High-Performance Nanostructured Ce-Fe-B Magnetic Materials via Electron-Beam Exposure

Abstract

Low magnetocrystalline anisotropy and energy product of the Ce 2 Fe 14 B compound severely restrict its application in permanent magnet applications, in spite of its potential as a novel permanent magnet alternative based on a widely abundant and inexpensive rare-earth (Cerium). A novel strategy combining melt-spinning and electron-beam exposure (EBE) aiming for fabricating high-performance Ce-Fe-B magnet is reported in this work. Remarkably, this strategy facilitates developing a suitable grain boundary configuration without using any additional heavy rare-earth element. Under the optimal EBE condition, the maximum energy product ( (BH) max ) of pure Ce-Fe-B alloy is 6.5 MGOe, about four times higher than that obtained after conventional rapid thermal process (RTP) method for the same precursor . This suggest that CeFeB materials using EBE could be a promising candidate after further processing, such as hot deforming or sintereing, to fill the performance “gap” between hexaferrite and Nd-Fe-B-based magnets. The enhanced intergranular magnetostatic coupling effect in EBE sample is further validated by mapping FORC diagrams. The in-situ observation of magnetic domain wall motion for Ce-Fe-B alloy using Lorentz transmission electron microscopy reveals that the boundary layers are very effective in pinning the motion of domain walls, leading to the increased coercivity under EBE. Micromagnetic simulations are also performed to verify the pinning effect of grain boundary configuration in the Ce-Fe-B system.