Coercivity temperature dependence of Sm2Co17-type sintered magnets with different cell and cell boundary microchemistry
Autor: | Kuikui Song, Wei Li, Minggang Zhu, Liwei Song, Nengjun Yu, Yikun Fang, Qiang Wang |
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Rok vydání: | 2018 |
Předmět: |
010302 applied physics
Materials science Analytical chemistry Boundary (topology) 02 engineering and technology Coercivity 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences Electronic Optical and Magnetic Materials Sintered magnets Transmission electron microscopy Phase (matter) Magnet 0103 physical sciences 0210 nano-technology Spectroscopy |
Zdroj: | Journal of Magnetism and Magnetic Materials. 452:272-277 |
ISSN: | 0304-8853 |
Popis: | High maximum energy product ((BH)max) Sm(CobalFe0.18Cu0.07Zr0.03)7.7 magnet (type-A) and high temperature Sm(CobalFe0.1Cu0.09Zr0.03)7.2 magnet (type-B) were prepared by a traditional powder metallurgical technology. A record (BH)max of 98.7 kJ/m3 with a coercivity (Hcj) of 501.5 kA/m at 773 K was achieved for the type-B magnet, which is much higher than that of type-A magnet (63.7 kJ/m3). The microstructures of the magnets were revealed by high-resolution transmission electron microscope. The average cell size of the type-A and B magnet are 110 nm and 90 nm, respectively. Moreover, the type-B magnet shows a wider cell boundary than the type-A magnet. Additionally, the element distribution of the cell/cell boundary interfaces was measured by energy-dispersive spectroscopy. The cell phase of the type-A magnet contains a higher Fe content as about 17 at%, comparing with that of the type-B magnet (∼8.9 at%). On the other hand, the Cu content of the cell boundary phase is 18 at% almost twice higher than the type-B magnet (8.6 at%). Theoretical Hcj temperature dependence of these two kinds of magnets indicates that the lower Cu content in the cell boundary phase and the appropriate Fe content in the cell phase are the key factors for the high Hcj for the type-B magnet at elevated temperature. |
Databáze: | OpenAIRE |
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