Relationships between localized-mode phonon energy and thermal transport properties
| Project/Area Number |
20H02459
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Review Section |
Basic Section 26040:Structural materials and functional materials-related
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| Research Institution | Tohoku University |
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Principal Investigator |
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Project Status |
Completed (Fiscal Year 2022)
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| Budget Amount *help |
¥18,200,000 (Direct Cost: ¥14,000,000、Indirect Cost: ¥4,200,000)
Fiscal Year 2022: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
Fiscal Year 2021: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2020: ¥11,960,000 (Direct Cost: ¥9,200,000、Indirect Cost: ¥2,760,000)
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| Keywords | 熱伝導 / 格子振動 / フォノン分散 / 非調和振動 / 熱伝導率 / フォノン / 非調和性 |
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| Outline of Research at the Start |
クラスレートやスクッテルダイト化合物などの包接化合物には，内包原子の局在フォノンモードが存在し，極めて低い格子熱伝導率を示すことが知られているが，その具体的な起源は明らかになっていない．局在フォノンモードのエネルギー準位およびエネルギー分布と格子熱伝導率の相関性から，低格子熱伝導率の起源を明らかにした上で，電場や磁場で内包原子の移動拡散や偏位を操作することにより格子熱伝導率を変化させられる熱伝導制御材料の設計指針を得ることを目指す．
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| Outline of Final Research Achievements |
To control the transport of highly diffusive heat on a micro scale, it is essential to have a thermal switching mechanism that can reversibly switch the heat flow on and off in a simple way without mechanical driving parts. In this study, the effect of thermal vibration of guest atoms in inclusion compounds on the lattice thermal conductivity was investigated to obtain a design guideline for thermal switching materials in which the thermal conductivity can be drastically changed by manipulating guest atoms in an external field. The results showed that anharmonicity, rather than the localization of thermal vibration, strongly governs the lattice thermal conductivity.
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| Academic Significance and Societal Importance of the Research Achievements |
物質の熱伝導率の起源については現代において不明な点が多い．本研究では，包接化合物と呼ばれるホストゲスト型の構造を有する場合，ゲスト原子の熱振動，特にその非調和性が格子熱伝導率低減に大きく寄与していることを明らかにした．本研究で得られた知見は低い熱伝導率が求められる熱電変換材料の研究開発にも応用できると考えられ，工業的重要度も高い．
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Report
(4 results)
Research Products
(17 results)
