| 研究課題/領域番号 |
20J14631
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| 研究種目 |
特別研究員奨励費
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| 配分区分 | 補助金 |
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| 応募区分 | 国内 |
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| 審査区分 |
小区分26020:無機材料および物性関連
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| 研究機関 | 東京大学 |
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研究代表者 |
楊 楚楚 東京大学, 工学系研究科, 特別研究員(DC2)
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| 研究期間 (年度) |
2020-04-24 – 2022-03-31
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| 研究課題ステータス |
完了 (2021年度)
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| 配分額 *注記 |
2,100千円 (直接経費: 2,100千円)
2021年度: 1,000千円 (直接経費: 1,000千円)
2020年度: 1,100千円 (直接経費: 1,100千円)
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| キーワード | Al2O3 / grain boundary / segregation / diffusion / alumina / STEM |
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| 研究開始時の研究の概要 |
This research will accurately measure the atomic structures and the trace elements states in the grain boundaries of Al2O3, in order to understand the relationship between the structures and the physical properties of materials, which will help design high-performance ceramic materials.
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| 研究実績の概要 |
Small concentrations of dopants that diffuse and segregate to the grain boundaries can significantly change the properties of polycrystalline Al2O3. The purpose of this research is to reveal the mechanisms of dopants segregation and diffusion in grain boundaries. Firstly, pristine and Y-doped Al2O3 grain boundaries were fabricated by the bicrystal method. By using atomic resolution STEM and EDS mapping, the grain boundary structural transformation and segregation of both Y and Ca were clearly revealed. The preferential segregation of Y and Ca to the same sites was observed, mainly due to the ionic size mismatch between dopants and the host Al. On the other hand, atomistic Ti diffusion behaviors in Al2O3 grain boundaries were investigated, by controlling the diffusion length and precisely preparing the TEM sample. The diffusion coefficients along two mutual vertical directions of the grain boundary were directly determined and the atomic structures of the structural transition areas were characterized. These results further deepen our understanding of dopants segregation and diffusion behaviors and provide important guidance towards the design of Al2O3 ceramics with better performance.
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| 現在までの達成度 (段落) |
令和3年度が最終年度であるため、記入しない。
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| 今後の研究の推進方策 |
令和3年度が最終年度であるため、記入しない。
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