2021 Fiscal Year Final Research Report
Control of metal-insulator transition of Ti2O3 films by epitaxial strain
Project/Area Number |
19H02588
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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 |
Review Section |
Basic Section 29020:Thin film/surface and interfacial physical properties-related
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Research Institution | Tohoku University |
Principal Investigator |
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Project Period (FY) |
2019-04-01 – 2022-03-31
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Keywords | Ti2O3 / 金属絶縁体転移 / 薄膜 / パルスレーザ堆積法 / 強相関酸化物 |
Outline of Final Research Achievements |
In this study, we investigated the mechanism of the metal-insulator transition of Ti2O3, which is one of the typical transition-metal oxides, using a thin-film form. We found that the degree of lattice deformation was modulated in the growth conditions. Especially, the film grown on low temperatures extended along the out-of-plane direction and exhibited metallic ground states without showing the metal-insulator transition. We also performed angle-resolved photoemission spectroscopy to reveal the electronic structures in momentum space. We found that the experimental and calculated band structures were in good agreement with each other in Ti2O3.
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Free Research Field |
酸化物エレクトロニクス
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Academic Significance and Societal Importance of the Research Achievements |
典型的なd1電子系の単純酸化物にも関わらず、三酸化二チタン(Ti2O3)では温度変化で示す相転移の起源は未だ明らかになっていない。Ti2O3は温度変化による結晶格子の変形も大きいため、相転移が温度で発現する現象なのか、格子変形で発現する現象なのかが明らかにできていない。本研究では基板応力により格子変形が可能な薄膜を用いることで、今までのバルク体研究では解明不可能な相転移と格子変形の関係を明らかにした。合成条件により室温での格子変形度合いを任意に制御することで、Ti2O3で発現する金属絶縁体転移が温度によらず、特定の格子変形度合いで発現することを見出した。
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