High-performance permanent-magnet materials based on CeFe12

Abstract

We perform first-principles calculations on the Mo/Zr-alloyed ThMn12-structure prototype CeFe12 to explore its electronic and magnetic properties and potential for permanent magnet applications. A recent experiment has shown that the Mo/Zr-alloyed CeFe12 phase with the symmetry 𝐼⁢4/𝑚⁢𝑚⁢𝑚 can be stabilized in bulk. It encourages an investigation into the intrinsic magnetic characteristics of the base structure CeFe12 and the effect of transition metal alloying in it. Our calculations reveal that the base structure prototype CeFe12 in its tetragonal phase exhibits uniaxial magnetic anisotropy with a magnetic anisotropy energy (𝐾1) ∼1MJ/m−3 and a substantial magnetic moment of ∼1.8T, showing its promise as a permanent magnet. The introduction of the stabilizing transition metals Zr, Mo, and W reduces these values but still keeps the materials very promising. Notably, when 50% of Ce is substituted by Sm in Mo-alloyed CeFe12, the 𝐾1 is significantly enhanced, accompanied by a fairly decent magnetic moment of ∼1.2T. These findings establish this alloy as a strong candidate for high-performance permanent magnet applications. This study emphasizes the importance of strategic element substitution and site selection in transition metal-alloyed CeFe12 to achieve both structural stability and remarkable magnetic properties.