Rare earths alternative in magnets

BalorNG

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https://www.cam.ac.uk/research/news/new-approach-to-cosmic-magnet-manufacturing-could-reduce-reliance-on-rare-earths-in-low-carbon

Now that is interesting.

https://onlinelibrary.wiley.com/doi/full/10.1002/advs.202204315

While the hard-magnetic properties of tetrataenite are attractive, those demonstrated so far do not surpass those of Nd2Fe14B,[1, 2] although the maximum energy product of meteoritic samples may have been underestimated.[25] The properties would be improved by increasing the degree of chemical order,[18] as shown in the present work to be possible by annealing. Ab-initio calculations suggest that judicious alloying can increase saturation magnetization, coercivity, and magnetocrystalline anisotropy.[30, 31]

The present castings and microstructures would be far from optimal for a high-performance permanent magnet; we have not, for example, applied a magnetic field to polarize our samples (as in the pioneering studies[3, 26]). Yet the wide processing window revealed in the present work facilitates exploration of compositions to achieve industrial-scale synthesis of tetrataenite. Tetrataenite thus obtained would not only provide useful permanent-magnet performance in the wide range between ferrites and Nd2Fe14B[2] but could also attain properties rivaling those of the best rare-earth-based magnets.


Sounds almost too good to be true... I wonder about Curie temperature.
 
A bit more on the alloy.
"Tetrataenite"
 
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