Achievement of high coercivity in Sm(Fe0.8Co0.2)12 anisotropic magnetic thin film by boron doping
| Autor: | G. Saito, D. Ogawa, Yukiko Takahashi, Tadakatsu Ohkubo, Toshiyuki Shima, Y. Tamazawa, Masaaki Doi, Satoshi Hirosawa, Kazuhiro Hono, M. Kambayashi, Hossein Sepehri-Amin |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Polymers and Plastics Condensed matter physics Metals and Alloys 02 engineering and technology Coercivity 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Electronic Optical and Magnetic Materials Amorphous solid Domain wall (magnetism) Remanence Magnet 0103 physical sciences Scanning transmission electron microscopy Ceramics and Composites Grain boundary 0210 nano-technology |
| Zdroj: | Acta Materialia. 194:337-342 |
| ISSN: | 1359-6454 |
| Popis: | SmFe12-based compounds have been considered as promising candidates for next generation permanent magnet materials because of their excellent intrinsic hard magnetic properties with a minimum usage of rare earth elements. However, realizing high coercivity in anisotropic microstructure is a big challenge, which hinders their practical applications. In this work, a novel anisotropic granular microstructure of Sm(Fe0.8Co0.2)12 with a sufficiently large coercivity (µ0Hc) of 1.2 T and with a high remanent magnetization of 1.50 T is demonstrated in thin films prepared by co-sputtering Sm(Fe,Co)12 with boron. Detailed microstructure characterization using high resolution scanning transmission electron microscopy (STEM) and atom probe tomography (APT) indicate that the addition of B leads to the development of columnar-shaped Sm(Fe0.8Co0.2)12 grains with a size of ∼40 nm, which are surrounded by ∼3 nm-thick B-enriched amorphous intergranular phase. Domain wall pinning at the amorphous grain boundary phase is attributed to the high coercivity. This work provides a guiding principle for realizing high-coercivity anisotropic SmFe12-based permanent magnets, which can outperform Nd-Fe-B magnets and could be used as the next-generation high-performance permanent magnets in various applications. |
| Databáze: | OpenAIRE |
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