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New structural features and pinning-evolved coercivity mechanism: A potential route for developing high coercivities in anisotropic Sm-Fe-N material
- Source :
- Journal of Materials Research and Technology, Vol 30, Iss , Pp 451-460 (2024)
- Publication Year :
- 2024
- Publisher :
- Elsevier, 2024.
-
Abstract
- Sm-Fe-N material holds immense promise as new material for developing next generation permanent magnets. However, the achievement of high coercivity in this material remains a big challenge, and moreover new coercivity theories beyond the commonly considered nucleation-type mechanism needs exploration. This study describes both the yielding of anisotropic Sm-Fe-N powders with high coercivities and the discovery of new coercivity mechanism by a systematic study using a designed milling preparation method. As a result, a random-direction cleavage behavior with unexpected XRD peak shifts and formation of new micron-sized flower-like particles were found in the yielded Sm-Fe-N powders. The grain sizes of the powders are of nanoscale dimension and they refine gradually as the milling time increases. The measured coercivity is up to 15.0 kOe, which is a substantial increase of approximately 36.4% compared to the original commercial powders and among the highest reported values via the milling preparation method (commonly below 13 kOe). The yielded powders also demonstrate a new dual-type coercivity mechanism (combing both nucleation-type and pinning-type control effect), and the improved pining effect contributes to the high coercivities. This study opens the door of utilizing pinning effect for achieving high coercivities in anisotropic Sm-Fe-N material.
Details
- Language :
- English
- ISSN :
- 22387854
- Volume :
- 30
- Issue :
- 451-460
- Database :
- Directory of Open Access Journals
- Journal :
- Journal of Materials Research and Technology
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.b2141b47cb4d456fabac6ab7dbda577d
- Document Type :
- article
- Full Text :
- https://doi.org/10.1016/j.jmrt.2024.03.040