New hard magnetic materials with reduced Co content 

Predicted formation energy (top), magnetic anisotropy (middle), and energy product for LaCo5-xFexN2-y compounds
Predicted formation energy (top), magnetic anisotropy (middle), and energy product for LaCo5-xFexN2-y compounds

CMI researchers at Ames Laboratory conducted the research for this CMI highlight

Achievement
LaCo2Fe3N2 and LaCo2Mn3N2 with reduced Co are found from first principles to exhibit significant hard magnetic properties.

Significance and impact

  • Intermediate-performing, critical element-lean permanent magnet materials offer promise of low-cost “gap-magnets”
  • Substitution of Fe and Mn for Co reduces materials cost by as much as 55%, relative to LaCo5

Details and next steps

  • Interstitial nitrogen inclusion stabilizes compositions and enhances intrinsic permanent magnet properties
  • Future studies will determine whether nitrogen addition induces  structural transformation from 1-5 into 1-12 or 2-17 structures