About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in Magnetism and Magnetic Materials
|
| Presentation Title |
Tailoring α-Fe2O3 Precursor Microstructure to Enhance Coercivity in Rare-Earth-Free α″-Fe16N2 Powders |
| Author(s) |
Ji-hyeong Jeong, Hye Young Koo, Jung-Goo Lee, Youn-Kyoung Baek |
| On-Site Speaker (Planned) |
Ji-hyeong Jeong |
| Abstract Scope |
High-purity and high-coercivity α″-Fe16N2 microparticles were synthesized by modifying the initial microstructure of α-Fe2O3 precursors using aerosol processing. Three distinct α-Fe2O3 powders were prepared through spray pyrolysis of Fe(NO3)3 (SP-nitrate) and spray drying, followed by calcination of Fe(NO3)3 (SD-nitrate) or Fe2(C2O4)3 (SD-oxalate). Following identical H2 reduction and NH3 nitridation, the resulting powders exhibited high α″-Fe16N2 phase fractions of 90-95 wt% and similar crystallite sizes of approximately 17-18 nm, while coercivity varied systematically from 1.14 to 1.86 kOe. The SD-oxalate route yielded the most intricate and porous particle morphology. Subsequent reduction and nitridation increased this porosity, generating numerous pore walls, edges, and rough surfaces that could serve as domain-wall pinning sites, consistent with the highest coercivity. These findings suggest that adjusting the aerosol route and precursor chemistry to regulate the precursor microstructure offers a practical and scalable approach to enhance the coercivity of rare-earth-free α″-Fe16N2. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Magnetic Materials, |