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

Materials & Design

Seok Namkung¹  M.J. Kim¹  Qingxiao Wang¹  Hui-Youn Shin¹  Yaoqiao Hu²  Xiangyu Zhu²  Myungshin Choi²  Minho Joo³  Namseok Kang³  Sunyong Song³  Byung Oh Jung³ 

[1] Devices Advanced Research Institute, LG Electronics, LG Science Park, 10, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Korea;Department of Materials Science and Engineering, University of Texas Dallas, 800 W Campbell Rd, Richardson, TX 75080, USA;;Materials &

关键词: NdCeFeB;    Phase transformation;    Microstructure;    STEM;    In-situ heating;   

DOI  :  

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown