Project/Area Number |
18K18806
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Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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Allocation Type | Multi-year Fund |
Review Section |
Medium-sized Section 18:Mechanics of materials, production engineering, design engineering, and related fields
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Research Institution | Kyoto University |
Principal Investigator |
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Co-Investigator(Kenkyū-buntansha) |
澄川 貴志 京都大学, 工学研究科, 准教授 (80403989)
嶋田 隆広 京都大学, 工学研究科, 准教授 (20534259)
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Project Period (FY) |
2018-06-29 – 2020-03-31
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Project Status |
Completed (Fiscal Year 2019)
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Budget Amount *help |
¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
Fiscal Year 2019: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
Fiscal Year 2018: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
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Keywords | 格子欠陥 / ナノひずみ場 / 強誘電性 / マルチフィジックス特性 / 第一原理解析 |
Outline of Final Research Achievements |
To overcome the critical nano-dimensions where ferroelectricity disappears and to mechanically design ultra-small ferroelectrics with atomic and lattice scales, we have performed in-situ mechanical tests and first-principles analysis based on quantum mechanics for dislocation cores in SrTiO3. We find that a spontaneous intrinsic strain field is formed at the dislocation core, and this strain field induced the ferroelectricity with a few crystal lattice sizes. Therefore, the dislocation core itself can be regarded as a atomic (or lattice)-scale ferroelectric material. In addition, mechanical testing and analyses for nano-ferroelectrics have been carried out and then we clarify the coupling effect between strain and ferroelectricity (multiphysics properties).
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Academic Significance and Societal Importance of the Research Achievements |
本研究は、臨界寸法以下の強誘電性は存在し難いという前例を覆し、格子欠陥が有する固有のひずみ場によって力学的に原子スケールの強誘電体をつくり出す点や、機能と力学的変形の相互作用であるマルチフィジックス原理を解明し、力学-強誘電性間の異種物理特性が作用する新しい力学を提案する点に学術的意義がある。特に、マルチフィジックス特性は、ひずみシリコンなどの応用例のように電子デバイスへの利用が始まっていることから、本研究成果によってより高度なナノデバイス設計や全く新しい技術・製品開発に繋がると考えられる。
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