| Project/Area Number |
17K14805
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | Hokkaido University |
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Principal Investigator |
Saito Genki 北海道大学, 工学研究院, 特任助教 (00749278)
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| Project Period (FY) |
2017-04-01 – 2019-03-31
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| Project Status |
Completed (Fiscal Year 2018)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2017: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
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| Keywords | 電子顕微鏡 / 三次元観察 / HAADF / STEM / セラミックス / 蛍光体 / 透過型電子顕微鏡 / ドーパント / 解析・評価 / HAADF-STEM / 3Dイメージング |
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| Outline of Final Research Achievements |
Three-dimensional (3D) distributional analysis of individual dopant atoms in materials is important to understand their properties. In this study, through-focus high-angle annular dark-field (HAADF) imaging was developed for 3D distributional analysis of dopant atoms in phosphors, in which the defocus was changed in narrow steps, and the contrast profile obtained for various depths at each dopant column was analyzed to determine the depth position of dopant atoms. For the analysis of Eu atoms in Ca-α-SiAlON, the effect of convergence semi-angle was investigated using multi-slice image simulation. Because the electron beam tends spread instead of channeling along the atomic columns, the large convergence semi-angle greatly increased the depth resolution. Through-focus HAADF-STEM imaging was used to analyze the Eu atom distribution. The contrast depth profile recorded with a narrow step width clearly analyzed the possible depth positions of Eu atoms.
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| Academic Significance and Societal Importance of the Research Achievements |
(1) X線などを用い、平均的な情報から原子の分布を解析する方法と異なり、ドーパント原子を直接観察するため、定量性の高い分析が可能となる。
(2) 開発したドーパント原子の三次元可視化技術はαSiAlON蛍光体に限らず、他のセラミックス、金属全般に広く適用可能であり、本研究によりこれら関連分野のさらなる発展が期待できる。
(3) 像シミュレーションは実験結果とよく一致し、原子の可視化可能性を事前の像計算で判断できる。
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