Enhanced hard magnet properties – Sm2Fe17N3-based powders

line graph with blue line above a black line
XRD demonstrating the phase purity of produced Sm2Fe17N3 material.

CMI researchers from Ames National Laboratory conducted the activity for this highlight

Post-processing produces phase-pure Sm2Fe17N3 powders with improved hard-magnetic properties. Direct conversion of Sm2Fe17 phase from Sm2O3  was performed using dispersant-assisted reduction-diffusion (RD).

Removing reaction by-products without degrading the magnetic phase is critical to achieving improved hard-magnetic properties with a record (BH)max of 22.3 MGOe and 88.7% magnetic squareness ratio.

Significance and Impact

  • Criticality and cost: the material is mostly Fe (~74% wt.%), containingnon-critical rare earth, Sm, as well as the earth-abundant constituent, N.
  • Next step is to form fully dense Sm2Fe17N3-based materials, comprising single grains and particles that may rival Neo magnets in performance.

Hub Target Addressed 
Accelerated magnet discovery and maturation.

graph with blue and red lines -- blue represents post-processing, and red the as-prepared sample
Hysteresis loops of as-prepared and post-processed Sm2Fe17N3 powders, demonstrating greatly improved properties.