
CMI researchers from the Ames National Laboratory conducted the activity for this highlight
Innovation
Direct conversion of Sm2O3 into Sm2Fe17 phase via reduction-diffusion (RD) produces pure Sm2Fe17N3 powders with improved hard-magnetic properties.
Achievement
Developed dispersant-assisted reduction diffusion (RD) approach to improve hard magnetic properties and phase purity. RD at 950°C produced high-purity (98%) Sm2Fe17N3 powders that on sintering produced a bulk magnet with (BH)max = 16.5 MGOe and 86% relative density.
Significance and Impact
- Criticality and cost: the material is mostly Fe (~74% wt.%) and non-critical rare earth, Sm, as well as earth-abundant nitrogen.
- When fully developed, single grain-single particle Sm2Fe17N3-based materials are expected to partially replace heavy rare earth Nd-based magnets in high performance, high temperature applications due to superior temperature dependence and likely lower cost.
Hub Goal Addressed
Reducing critical rare-earth content in permanent magnets through development and deployment of novel magnets with improved hard-magnetic properties.
R. Kuchi, D. Schlagel, T. S. Cozzini, J. V. Zaikina, I. Z. Hlova, “Exploiting Mechanochemical Activation and Molten-Salt-Assisted Reduction-Diffusion Approach in Bottom-up Synthesis of Sm2Fe17N3," J. All. Comp., 2023, in press. https://doi.org/10.1016/j.jallcom.2024.173532