New Co-Fe-N Magnetic Compounds Found Through Combined Computational and Experimental Methods*

A combined search using computational and non-equilibrium cluster-deposition methods has been efficient in accelerating the discovery of new magnetic materials with high magnetocrystalline anisotropy K₁, large saturation magnetic polarization J_s, and high Curie Temperature T_c [1, 2]. Here we present the structure and magnetism of new compounds created by incorporating nitrogen and/or silicon in the interstitial or substitutional occupancies of Co, Fe, and FeCo. The search found a set of Fe-Co-N compounds having promising magnetic properties, including tetragonal Fe₈Co₈N₂ that exhibits K₁ = 16 Mergs/cm³, J_s = 17.6 kG, and T_c ≈ 650 K. The prospects of new rare-earth magnetic compounds for energy and information storage applications will be discussed.
References
[1] B. Balasubramanian, M. Sakurai, C.-Z. Wang, X. Xu, K.-M. Ho, Chelikowsky, and D.J. Sellmyer Mol. Syst. Des. Eng., 5, 1098 (2020).
[2] M. Sakurai et al. Discovering rare-earth-free magnetic materials through the development of a database, Phys. Rev. Mater. (in press).