Search for novel physical properties in spin-orbit fluctuated systems
| Project/Area Number |
18K03543
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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 13030:Magnetism, superconductivity and strongly correlated systems-related
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| Research Institution | Kagoshima University |
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Principal Investigator |
Okuda Tetsuji 鹿児島大学, 理工学域工学系, 准教授 (20347082)
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| Co-Investigator(Kenkyū-buntansha) |
梶本 亮一 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 J－PARCセンター, 研究主幹 (30391254)
齋藤 智彦 東京理科大学, 理学部第一部応用物理学科, 教授 (30311129)
桑原 英樹 上智大学, 理工学部, 教授 (90306986)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2020: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2019: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
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| Keywords | 強相関電子材料 / 二量体 / 電荷整列 / 熱電特性 / 擬ブルッカイト / 強相関電子系 / 擬ブルッカイト型Ti酸化物 / スピン・軌道揺らぎ / 強相関電子系物質 / 希釈磁性半導体 / フラストレート磁性体 |
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| Outline of Final Research Achievements |
In this project, we searched for novel physical properties in chemically substituted pseudobrookite Ti3O5 with enhanced spin-orbit fluctuations. In the low temperature β phase of Ti3O5, a spin-singlet dimerization between the neighboring Ti3+ ions occurs with accompanying Ti3+/Ti4+ charge ordering. We succeeded in growth of the single crystals mixed with AlTi2O5 having the similar structure and found that the α, λ, and β phases sequentially appeared at room temperature with the change in the Al content and that the correlated conductive state where the dimer correlations strongly remained were realized even in the paramagnetic α and λ phases. Furthermore, we found unique magnetic properties and relatively good high-temperature thermoelectric properties, originating in the fluctuations of dimerization, near the phase boundary between the λ and β phases.
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| Academic Significance and Societal Importance of the Research Achievements |
スピン一重項の二量体形成は一般的な量子現象であり、Ti3O5やTi4O7の低温での二量体形成は古くから知られていた。ところが、Ti3O5のλ相やTi4O7の中間相ではバイポーラ・スピン液体状態や異常コヒーレント状態などが提案されており、それらの磁気・電子状態は未解明のままであった。さらに、近年、理論や実験の進展に伴い、スピン・軌道整列が起源となる多量体形成が多くの物質で見出され、その物性研究が進展しつつある。以上の背景のもと、本課題で育成に成功した元素置換したTi3O5やTi2O3の単結晶での発見は、二量体物性の理解を深化させ、さらに、巨大熱電応答など新量子物性につながる重要なものと思われる。
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Report
(2 results)
Research Products
(8 results)
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[Journal Article] Elastic and dynamical structural properties of La and Mn-doped SrTiO3 studied by neutron scattering and their relation with thermal conductivities2018
Author(s)
Ryoichi Kajimoto, Mitsutaka Nakamura, Naoki Murai, Shin-ichi Shamoto, Takashi Honda, Kazutaka Ikeda, Toshiya Otomo, Hiroto Hata, Takahiro Eto, Masaaki Noda, Hideki Kuwahara, Tetsuji Okuda
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Journal Title
Scientific Reports
Volume: 8
Issue: 1
DOI
Related Report
Peer Reviewed / Open Access
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