| Project/Area Number |
18K03477
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 13020:Semiconductors, optical properties of condensed matter and atomic physics-related
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| Research Institution | Hirosaki University |
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Principal Investigator |
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| Project Period (FY) |
2018-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2020: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
Fiscal Year 2019: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000)
Fiscal Year 2018: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
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| Keywords | 誘電異常 / 電子構造 / X線ラマン散乱 / 共鳴X線非弾性散乱 / X線発光 / 蛍光X線ホログラフィー / 高圧実験 / Aサイト秩序ペロブスカイト / X線散乱 / 誘電体 |
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| Outline of Final Research Achievements |
A-site ordered perovskite CaCu3Ti4O12（CCTO） shows a giant dielectric constant within a wide temperature-range include the room temperature, while it shows dielectric anomaly as rapid decrease of the dielectric constant at about 100K without structure change. Soft and hard X-ray Raman scattering (XRS) and X-ray fluorescence holography (XHF) measurements were performed in Photon Factory, KEK. Unoccupied Cu 3d and Ti 3d states and occupied O 2p state were studied using the XRS. The Cu 3d state increased rapidly at about 100K, then it suggests an effect of electronic structure to the dielectric anomaly. In the XHF experiments, an ordering of Ti-site was found under 100K.
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| Academic Significance and Societal Importance of the Research Achievements |
CaCu3Ti4O12のような絶縁体（誘電体）における電子構造の研究は非常に難しい。本研究におけるX線ラマン散乱の実験は、誘電体の電子構造研究に強力な手法となると考えられる。XRS実験によって、巨大誘電率や誘電異常など誘電的性質に対する電子構造の効果を明らかにされることが期待される。誘電体を用いたデバイスの性能向上などにも寄与するものと考えられる。
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