Large magnetic anisotropy in 4f-electron-free ferromagnets

The honeycomb and Kagome layers (top) of the YCo5 structure associated with the flat bands (bottom) and large magnetic anisotropy in this material.
The honeycomb and Kagome layers (top) of the YCo5 structure associated with the flat bands in this material. 

CMI researchers from Oak Ridge National Laboratory conducted the activity for this highlight

Innovation
A thorough analysis was conducted to determine the origin of magnetic anisotropies exceeding those of Nd2Fe14B in 4f-electron free ferromagnets such as YCo5 and LaCo5. 

Achievement
The electronic structure is characterized by a set of narrow 3d bands near the Fermi level. In YCo5, easy-axis anisotropy originates from spin-orbit coupling mixing the states from Co atoms arranged in a combination of honeycomb and Kagome lattices.

Significance and Impact
The findings suggest the importance of Kagome-type structures with flat Fermi-level bands as a criterion for the development of new magnets.

Hub Target Addressed 
Accelerated discovery and deployment of new permanent magnets. 

G. D. Samolyuk, K. D. Belashchenko, and D. S. Parker, “On the origin of magnetic anisotropy in 4f-free ferromagnets based on the CaCu5 structure”, J. Phys.: Condens. Matter,  https://doi.org/10.1088/1361-648X/ad673a., 2024. 

The honeycomb and Kagome layers (top) of the YCo5 structure associated with the flat bands (bottom) and large magnetic anisotropy in this material.
The large magnetic anisotropy in this material.