High-Temperature Ferromagnets From Early Transition Metals?

Early transition metal intermetallics often display quite complex magnetic behavior, in view of the half or less-than-half-full 3d shell applicable to Chromium and Manganese. Even at an elemental level these display complex magnetic behaviors, with Chromium developing a spin-density-wave atop an antiferromagnetic background, and one of the numerous phases of Manganese exhibiting complex magnetism with no fewer than 58 atoms in the unit cell.

Given such complexity even in the elemental phases, one might expect further complexities in materials based on these elements, and this has been borne out in our recent work on the helimagnet Cr_1/3NbS₂ [1, 2, 3] and canted antiferromagnetism, with a small ferromagnetic component, in CsMn₂F₆ [4]. 

While much effort within the United States has been directed at finding new high-temperature ferromagnets based on Iron and Cobalt, there has been less success at finding new such materials based on Chromium or Manganese, despite the often high local moments associated with these elements. I discuss the prospects for new such ferromagnets in this materials class. 

References

1. 1. N. Sirica et al, Phys. Rev. B 104, 174426 (2021).
   
   2. N. Sirica et al. Comm. Phys. 3, 65 (2020).
   
   3. N.J. Ghimire et al, Phys. Rev. B 87, 104403 (2013).
   
   4. V.V. Klepov et al, J. Am. Chem. Soc. 143, 11554 (2021).