New structural features and pinning-evolved coercivity mechanism: A potential route for developing high coercivities in anisotropic Sm-Fe-N material

Liming Ye; Fengqing Wang; Yang Liu; Haoran Zhou; Lei Liu; Yong Ding; Yingli Sun; Aru Yan

Journal of Materials Research and Technology (May 2024)

New structural features and pinning-evolved coercivity mechanism: A potential route for developing high coercivities in anisotropic Sm-Fe-N material

Liming Ye,
Fengqing Wang,
Yang Liu,
Haoran Zhou,
Lei Liu,
Yong Ding,
Yingli Sun,
Aru Yan

Affiliations

Liming Ye: School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211, China; CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
Fengqing Wang: CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Corresponding author. CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
Yang Liu: CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
Haoran Zhou: CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China; University of Chinese Academy of Sciences, Beijing, 100049, China
Lei Liu: CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Corresponding author. CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
Yong Ding: CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China; University of Chinese Academy of Sciences, Beijing, 100049, China
Yingli Sun: CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China; University of Chinese Academy of Sciences, Beijing, 100049, China
Aru Yan: CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China; University of Chinese Academy of Sciences, Beijing, 100049, China

Journal volume & issue: Vol. 30
pp. 451 – 460

Abstract

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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.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

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