Intrinsic magnetism and practical potential of 2:14:1-type magnet with rare earth supplied only by misch-metal

2:14:1-type rare earth (R) permanent magnet R₂Fe₁₄B, as a functional material, plays an indispensable role in transportation, machinery, energy and other fields. Under the pressure of resources, cost and environment, special attention has been devoted to magnets replaced by high-abundance rare earth. But until now, 2:14:1 phase containing only misch-metal (MM) is not considered suitable for practical production. In this work, from the perspective of intrinsic properties, it is confirmed for the first time that MM₂Fe₁₄B with MM (La, Ce and other high-abundance rare earth content as high as 80%) has the potential to become a permanent material. The saturation magnetization M_s at 300 K is 27.36 μB/f.u, and the anisotropy parameters are μ₀H_a = 4.2 T, K₁ = 1.39 MJ/m³ and K₂ = 0.42 MJ/m³. We noted that the temperature dependence of M_s, K₁ and K₂ are very similar to Nd₂Fe₁₄B. Curie temperature T_C and spin reorientation temperature T_sr of MM₂Fe₁₄B are 488 K and 74 K, respectively. When the temperature is lower than T_sr, the anisotropy changes from easy-uniaxial to easy-cone. The spin reorientation angle θ_s is about 18° at 4.2 K, less than Nd₂Fe₁₄B. Small θ_s means that strong uniaxial anisotropy can be maintained, which is important to achieve high-performance. Micromagnetic simulation was also introduced to confirm the effect of θ_s and grain boundary on MM-Fe-B performance. The intrinsic magnetism not only provides strong evidence for the practicability of MM-Fe-B, but also of great significance for further study on the mechanism of rare earth magnets with high-performance and high-abundance.