2021 Fiscal Year Research-status Report
A search for Sm-based novel alloys for high temperature permanent magnet applications
| Project/Area Number |
21K14397
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| Research Institution | National Institute for Materials Science |
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Principal Investigator |
TOZMANKARANIKOLAS Pelin 国立研究開発法人物質・材料研究機構, 若手国際研究センター, ICYS研究員 (80868472)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Keywords | Bulk / Thin film / SmFe12 / Crystallography / Magnetic properties / Microstructure |
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| Outline of Annual Research Achievements |
Sm(Fe,Co)12-based compounds is considered as a potential next generation magnet owing superior intrinsic magnetic properties. Although, their phase stability in bulk can be established by substituting Fe atoms with phase stabilizing elements, M such as Ti, V, Si at the expense of magnetization. Apart from that magnetization enhancer Co is scarce element. I maintain magnetization in bulk by decreasing Co content (8.6 at.%) and Ti (2 at%) by partially substituting Sm with Y. For the case of V, I demonstrated that V is beneficial for Curie temperature enhancement and preservation of anisotropy field. This investigation is held in model thin film and bulk. It is found that V as a phase stabilizer have more merit than Ti-substituted ones for the development of high-performance magnet.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The results on SmFe12-based compounds are published in Applied Physics Expresss (IF: 2.9) and Acta Materialia (IF:8.2). Currently, I am minimizing V content for stabilizing 1:12 phase while keeping the equilibrium liquid phase in Sm-Fe-V and in Sm-Fe-V-Ag in bulk and model thin film. For the bulk state, I overcome the instability of 1:12 phase for less than 12 at.% of V by Zr addition. I obtained a mixture of Sm-Fe, Sm- and Sm-Ag intergranular phase in Sm0.8+xZr0.2FebalV1.2Ag0.4. Sm content is tuned to vanish elementary Fe which is detrimental for coercivity. The optimization on excess Sm against its evaporation and heat treatment are done for SmCo4B, SmCo3.8Fe0.2B and Sm0.7Nd0.3Co3.8Fe0.2B. 14 T applied field wasn't enough to determine their magnetization due to their large anisotropy.
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| Strategy for Future Research Activity |
For determining and understanding the source of the large anisotropy field of SmCo4B-based compounds a collaboration will be held with Tokyo University, Prof. Matsuda's lab. The M-H curves aligned SmCo4B fine powders in hard and easy axis will be measure under a 100 T field. Later, apart from the elemental substitution in SmCo4B, nanocomposite magnet with coexistence of Sm2Co17 and SmCo4B will be developed for enhancing further the magnetization. The liquid sintering process will be apply to V-lean (less than 12 at.%) alloy. This process has multiple steps (strip casting, jet milling, green compact and annealing) where each steps need further optimization in order to achieve desirable microstructure without the detrimental secondary phases (Fe, SmFe7).
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| Causes of Carryover |
This amount will be added to next fiscal year budget in order to buy consumables.
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