Fe substitution into SmCo5 for enhanced magnetic performance

Crystal structure of transition metal site substituted SmCo5. 1a, 2a and 3g sites are occupied by Sm, Co, and Fe, respectively for SmCo2Fe3.

CMI researchers at Ames Laboratory conducted the research for this highlight

Achievement
We identify an energetically preferred site in SmCo₅ for Fe substitution, increasing magnetization, without reducing magnetic anisotropy. Therefore, if synthesis of SmCo₂Fe₃ proves successful, this material may outperform SmCo₅.

Significance and impact
This achievement may yield a high BH_max, reduced Co high performance magnet, with likely similar operating temperatures and excellent temperature stability. Applications requiring high temperature stability and magnetic performance will have market penetration in the performance range between SmCo₅ and Nd₂Fe₁₄B.

Details and next steps
First principles all electron electronic structure calculations performed for magnetic characteristics of site substituted SmCo₅. Next step is to help experimental scientists to synthesize SmCo₂Fe₃ providing stability pathways from reaction kinetics and thermodynamics.

Magnetic anisotropy energy vs. orbital moment anisotropy