Synthesis of Ce-Based RE[sub.2]Fe[sub.14]B by Solid-State Reaction and Reduction-Diffusion Process

• Published in: Applied sciences 2024-12, Vol.14 (23)
• Main Authors: Lee, Sunwoo, Lee, Kanghyuk, Kang, Young-Min, Lee, Jung-Woo, Park, Jihoon, Yoo, Sang-Im, Park, Chan
• Format: Article
• Language: English
• Subjects: Cerium; Magnetic alloys; Magnetic properties; Magnetization; Magnets, Permanent; Powders; Production processes; Turbines
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app142311253

Rare-earth permanent magnets, such as Nd[sub.2]Fe[sub.14]B, have been widely used in electric vehicle and wind turbine motors due to their high anisotropy field (H [sub.a]), saturation magnetization (M [sub.s]) and coercivity (H [sub.c]). Cerium (Ce) has gained attention as a potential alternative to neodymium (Nd) due to its high abundance and low cost. The relatively poor intrinsic magnetic properties of Ce magnets, however, remain a significant challenge for their industrial applications. In this study, the synthesis of Ce-based RE [sub.2]Fe[sub.14]B (2-14-1) phases was achieved by a modified reduction-diffusion (R-D) process using REFeO[sub.3] (RE = Ce, Nd) as a precursor. The precursor was prepared by a solid-state reaction with CeO[sub.2], Nd[sub.2]O[sub.3], Fe[sub.2]O₃ and Fe powders, which is a much more suitable process for mass production and cost-effectiveness. Optimal composition and heat treatment conditions enabled the formation of single-phase Ce-based 2-14-1 particles. The as-synthesized single-phase Ce[sub.2]Fe[sub.14]B particles exhibited an M [sub.s] value of ~120 emu/g and an intrinsic coercivity (H [sub.ci]) value of ~85 Oe, which can be attributed to the large particle size as observed by FE-SEM.