Chemical synthesis of Nd₂Fe₁₄B/Fe–Co nanocomposite with high magnetic energy product

Abstract

Nd2Fe14B is one of the most popular permanent magnets (PMs) possessing the best energy product (BH)max among the common PM materials.

Crystallization kinetics of Ti-doped Nd₂Fe₁₄B/α-Fe nanocomposite permanent magnets

“…通过熔体快淬法和结晶过程制备的Nd 2 Fe 14 B/a-Fe纳米复合磁体, 由于软磁相a-Fe的结晶温度低 于硬磁相Nd 2 Fe 14 B, 常存在少量较大的a-Fe晶 粒. 故难以达到交换耦合纳米复合磁体的要求 [15] , 即需要同时控制两相的晶粒尺寸在10 nm以下. 这将导致Nd 2 Fe 14 B和a-Fe两相之间总的交换耦 合作用减弱, 最终降低复合磁体的磁性能.…”

Regulable Properties in Multicomponent Rare Earth Magnetic Particle SmxPr1–xCo5 by a Specially Designed Co Nanomatrix Precursor: Implications for Magnets with Different Application Temperatures

“…In contrast, the anisotropy field of PrCo 5 ( H A = 179 kOe) is much lower than that of SmCo 5 ( H A = 420 kOe). − Therefore, it is expected that SmCo 5 and PrCo 5 can be combined with appropriate composition to improve the M s of SmCo 5 compounds at the expense of moderate reduction of H A to obtain the optimal magnetic properties. , In addition, the magnets with the flexible option of properties can cope with different application requirements, especially different coercivity parameters for different operating temperatures. Many efforts have been made to obtain RE-Co particles with controllable magnetic properties by physical and chemical methods. ,− Pr doping in SmCo 5 is expected to obtain optimal magnetic performance, while the difficulty lies in controlling the composition homogeneity in multicomponent rare earth particles. Relative to physical methods, chemical methods are conducive to regulating particle size and morphology, which have a considerable impact on magnetic properties. − However, the preparation of RE-based particles by direct solution-based chemical synthesis is blindingly challenging because of the antioxidant chemical instability of RE.…”