2018 Fiscal Year Final Research Report
Physical properties of isotope diamond looking for further light element materials
Project/Area Number |
16H03861
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Crystal engineering
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Research Institution | Kwansei Gakuin University |
Principal Investigator |
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Co-Investigator(Kenkyū-buntansha) |
寺地 徳之 国立研究開発法人物質・材料研究機構, 機能性材料研究拠点, 主席研究員 (50332747)
石井 良太 京都大学, 工学研究科, 助教 (60737047)
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Research Collaborator |
Watanabe Hideyuki
Kushibiki Junichi
Tanno Takenori
Ogi Hirotugu
Nagakubo Akira
Majdi Saman
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Project Period (FY) |
2016-04-01 – 2019-03-31
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Keywords | 同位体 / 軽元素 / 電気・電子 |
Outline of Final Research Achievements |
In this study, we have focused on the physical properties of diamond which has a large influence on characteristics by isotope purification. High concentration of oxygen was applied to grow isotopically controlled diamond, and successfully obtained high quality 12C freestanding crystals. Regarding elastic properties, the ultra-precise lattice constant measurements were carried out for isotopically-enriched crystal by four-crystal symmetric reflection type X-ray diffraction. Also, the measurement using the Brillouin vibration method was performed to obtain the precise elastic constant of isotopically-enriched crystal. We have conducted photoluminescence and differential absorption spectroscopy under uniaxial stress at cryogenic temperatures and observed that free exciton transitions in 12Ccrystal are split by uniaxial stress for the first time. We also have succeeded in precise identification of the 12C and 13C bandgap difference and the isotope effect on phonons and excitons.
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Free Research Field |
電気・電子材料
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Academic Significance and Societal Importance of the Research Achievements |
同位体制御した結晶材料は、例えばシリコンでは材料物性そのものは不変であるが、軽元素のダイヤモンドで12C同位体濃縮した結晶は物質中最高の熱伝導がさらに1.5倍になるなど、「別物質」のような物性を有する。本研究では物性そのものにフォーカスして計測・解析を行い、同位体制御の効果が物性に及ぼす影響を研究した。高品質純化結晶の合成、弾性・光学物性の精密計測、新たな物性に関する知見などが得られた。周期律表の2周目の元素は、宇宙・地球に最も多く存在しており、同位体制御により「ありふれた軽元素から極めて有用な物質創生」できる可能性が大きく、今後化合物材料などへの展開が期待される。
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