In this study we investigate the finite-temperature magnetic properties of ${\mathrm{Sm}}_2{\mathrm{Fe}}_{17}{\mathrm{N}}_x$ $(x=0,3)$ using an effective spin model constructed based on the information obtained by first-principles calculations. We find that assuming the plausible trivalent ${\mathrm{Sm}}^{3+}$ configuration results in a model that can satisfactorily describe the magnetization curves of ${\mathrm{Sm}}_2{\mathrm{Fe}}_{17}{\mathrm{N}}_3$. By contrast, the model based on the divalent ${\mathrm{Sm}}^{2+}$ configuration is suitable to reproduce the magnetization curves of ${\mathrm{Sm}}_2{\mathrm{Fe}}_{17}$. These results expand the understanding of how electronic structure affects the magnetic properties of these compounds.

• Received 27 August 2020
• Revised 6 December 2020
• Accepted 10 December 2020

DOI:https://doi.org/10.1103/PhysRevB.102.214439