Considering the increasing demand for permanent magnets due to the development towards green technologies, cerium-containing neodymium-iron-boron ((Ce,Nd)-Fe-B) magnets have gained increasing interest as a strategic solution to mitigate the reliance on more critical rare earth elements (REEs) such as Nd, praseodymium (Pr), and dysprosium (Dy). Incorporation of Ce in Nd-Fe-B-based magnets can reduce the cost as well as balance the market demand and consider the natural abundance of REEs.

However, substituting Nd by Ce in the Nd₂Fe₁₄B phase poses a challenge for maintaining high magnetic performances due to the inferior intrinsic properties of the Ce₂Fe₁₄B phase. To moderate the deterioration, the 2-powder method (2PM) has been utilized. The method involves blending a finer anisotropy powder (AP) with a coarser main powder (MP), with both having a RE₂Fe₁₄B-based composition. The former powder is termed "anisotropy" considering the designed composition that gives a higher anisotropic field than the MP. After the standard sintering procedure, a core-shell structure, where the shell region exhibits a higher anisotropic field compared to the core part, can be formed homogeneously through the whole magnet without limitations in magnet sizes or shapes. This effective magnetic hardening of the grain surface leads to a remarkable improvement in coercivity.

Examining APs of Nd-Fe-B and (Nd,Dy)-Fe-B on the (Ce,Nd)-Fe-B MP reveals that the elemental distribution within the core-shell structure significantly influences magnetic performances. In magnets produced with (Ce,Nd)-Fe-B MP and Nd-Fe-B AP, a Nd-rich but Pr- and Ce-lean shell is formed, resulting in a 25% improvement in coercivity compared to magnets produced solely with MP. Notably, employing (Nd,Dy)-Fe-B AP yields an extraordinary 81% increase in coercivity without compromising remanence and energy product. This remarkable enhancement is attributed to the tendency of Dy to substitute Ce instead of Nd or Pr in the RE₂Fe₁₄B phase. The preference occupancies of different REEs in the shell region of RE₂Fe₁₄B grains are currently investigated in depth to make the 2PM optimally efficient.

In conclusion, the 2PM proves to be an effective strategy for improving the magnetic performance of (Ce,Nd)-Fe-B magnets. By carefully optimizing the RE composition in the MP and AP, magnetic performances can be tuned while minimizing the content of more critical REEs.