High-performance magnets based on Sm2Fe17

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graph showing magnetic anisotropy
Magnetic anisotropy as a function of Co concertation, x, in Sm2(Fe1-x Cox)14Al3

CMI researchers at Oak Ridge National Laboratory conducted the research for this highlight

Achievement
Theoretical calculations demonstrate that alloying with Cobalt  and Aluminum in Sm2Fe17 results in low-cost permanent magnet materials with excellent intrinsic properties.

Significance and impact
We propose a magnet based predominantly on Iron with low Cobalt content  (~15 % Co in Fe sublattice) and relatively inexpensive Samarium, with potential BHmax in the 20-30 MG-Oe range. 

Details and next steps

  • First principles calculations demonstrated that Sm2(Fe1-xCox)14Al3 is uniaxial with magnetic anisotropy energy ~8 MJ/m3 in range of Cobalt concentrations 13-18% (top figure).
  • The calculated magnetization at 13% Co substitution is 1.01 T.
  • Substitution of Cobalt into Sm2Fe16Al results in even larger uniaxial anisotropy in all range of Co concentrations.
  • Co substitution also increases Curie point significantly.

 

Magnetic anisotropy
Magnetic anisotropy as a function of Co concertation, x, in Sm2(Fe1-xCox)16 Al