Ce-based magnet with (BH)max of  20+ MGOe

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composite image: Upper figure: SEM images of two heat treated (HT) samples of the same Ce-magnet. After the regular (black) and modified (red) HT the 2:7-type intercalated regions and 2:7-type stacking faults form, respectively.  Lower figure: magnetic hysteresis loops. Record coercivity of ~10.6 kOe is achieved in the sample with uniform, anisotropic stacking faults. This yields (BH)max > 20 MGOe. 
Upper figure: SEM images of two heat treated (HT) samples of the same Ce-magnet. After the regular (black) and modified (red) HT the 2:7-type intercalated regions and 2:7-type stacking faults form, respectively. 

Lower figure: magnetic hysteresis loops. Record coercivity of ~10.6 kOe is achieved in the sample with uniform, anisotropic stacking faults. This yields (BH)max > 20 MGOe. 

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

Innovation
Novel cerium-based magnets for U.S. national needs.

Achievement:

  • Development of heat treatment (HT) procedure, which facilitates formation of 2:7-type stacking faults (instead of intercalated regions), strictly anisotropic and evenly dispersed within the matrix material. 
  • Microstructure yields development of record ~10.6 kOe (BH)max = 20.4 MGOe of coercivity and energy product, respectively.

Significance and Impact
Magnet is viable lower-cost competitor to SmCo magnets at lower Co content (43 wt.% vs. 53+%) using earth-abundant, inexpensive, industrial grade Cerium. 

Hub Goal Addressed
Win industry adoption of three technologies related to materials substitution for rare earth magnet materials.