Sm2Fe17N3 as a cost-effective high-performance magnet

image of a line graph showing powder X-ray diffraction patterns of as-washed and sintered material. — Powder X-ray diffraction patterns of as-washed and sintered material.

CMI researchers from Ames National Laboratory conducted the research for this highlight.

Innovation
Direct conversion of Sm₂O₃ into Sm₂Fe₁₇ phase via reduction-diffusion approach produces nearly oxygen-free, sinterable Sm₂Fe₁₇N₃ powders

Achievement
Magnet sintered at 420°C reaches a record relative density of 89% and demonstrates excellent hard-magnetic properties: remanence, Mr = 11.5 kG, and energy product BHmax = 23.5 MGOe.

Significance and Impact

Criticality and cost: the material is mostly Fe (~74% wt.%) and it contains non-critical rare earth, Sm, as well as other earth-abundant constituents
When fully developed, thermally-stable Sm₂Fe₁₇N₃–based materials are expected to become competitive with Nd₂Fe₁₄B-based magnets

Hub Goal Addressed
Reducing critical rare-earth content in permanent magnets via development of novel sinterable hard-magnetic materials.

Hysteresis loops of corresponding samples.