In-situ STEM study on thermally induced phase transformation of magnetic (Nd0.75Ce0.25)2Fe14B ribbons

Xiangyu Zhu; Byung Oh Jung; Qingxiao Wang; Yaoqiao Hu; Myungshin Choi; Sunyong Song; Seok Namkung; Namseok Kang; Hui-Youn Shin; Minho Joo; M.J. Kim

Materials & Design (Apr 2022)

In-situ STEM study on thermally induced phase transformation of magnetic (Nd0.75Ce0.25)2Fe14B ribbons

Xiangyu Zhu,
Byung Oh Jung,
Qingxiao Wang,
Yaoqiao Hu,
Myungshin Choi,
Sunyong Song,
Seok Namkung,
Namseok Kang,
Hui-Youn Shin,
Minho Joo,
M.J. Kim

Affiliations

Xiangyu Zhu: Department of Materials Science and Engineering, University of Texas Dallas, 800 W Campbell Rd, Richardson, TX 75080, USA
Byung Oh Jung: Materials & Devices Advanced Research Institute, LG Electronics, LG Science Park, 10, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Korea
Qingxiao Wang: Department of Materials Science and Engineering, University of Texas Dallas, 800 W Campbell Rd, Richardson, TX 75080, USA
Yaoqiao Hu: Department of Materials Science and Engineering, University of Texas Dallas, 800 W Campbell Rd, Richardson, TX 75080, USA
Myungshin Choi: Materials & Devices Advanced Research Institute, LG Electronics, LG Science Park, 10, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Korea
Sunyong Song: Materials & Devices Advanced Research Institute, LG Electronics, LG Science Park, 10, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Korea
Seok Namkung: Materials & Devices Advanced Research Institute, LG Electronics, LG Science Park, 10, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Korea
Namseok Kang: Materials & Devices Advanced Research Institute, LG Electronics, LG Science Park, 10, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Korea
Hui-Youn Shin: Materials & Devices Advanced Research Institute, LG Electronics, LG Science Park, 10, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Korea
Minho Joo: Materials & Devices Advanced Research Institute, LG Electronics, LG Science Park, 10, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Korea
M.J. Kim: Department of Materials Science and Engineering, University of Texas Dallas, 800 W Campbell Rd, Richardson, TX 75080, USA; Corresponding author.

Journal volume & issue: Vol. 216
p. 110525

Abstract

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Studying the phase transformation and microstructure evolution of magnetic Nd-Ce-Fe-B nanocrystalline melt-spun ribbon is of paramount significance in developing this important class of magnetic materials. In this work, the thermal-induced phase transformation of (Nd0.75Ce0.25)2Fe14B nanocrystalline sample was revealed via in-situ heating scanning transmission electron microscopy (STEM) experiment (RT-750 ℃). Starting from a single-phase (Nd0.75Ce0.25)2Fe14B nanocrystalline matrix at room temperature (RT), grain boundary (GB) diffusion behavior was investigated at an atomic scale. Our result shows that the rare earth elements accumulate at GB area from 200 °C and form a uniform thin amorphous layer between grains. The decomposition of the primary phase was observed at about 350 ℃ and crystalized as BCC-Fe, Fe2B, and (Nd0.75Ce0.25)2O3 phases driven by thermal activation at a higher temperature. This work provides the essential information of phase transformation and microstructure evolution of NdCeFeB-based magnets at high temperatures and new insights into thermal treatment designing and thermal stability considerations.

Published in Materials & Design

ISSN: 0264-1275 (Print); 1873-4197 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://www.journals.elsevier.com/materials-and-design

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