| Project/Area Number |
17K05524
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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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| Research Field |
Condensed matter physics II
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| Research Institution | Toyota Physical and Chemical Research Institute |
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Principal Investigator |
Ishimasa Tsutomu 公益財団法人豊田理化学研究所, フェロー事業部門, フェロー (10135270)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2017: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | 準結晶 / 価数揺動 / 量子臨界 / 希土類合金 / 近似結晶 / 新物質 / 正12角形準結晶 / 正20面体準結晶 / Yb合金 / 強相関系 / 金属物性 / 強相関電子系 / 結晶工学 |
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| Outline of Final Research Achievements |
Quasicrystals are a group of materials with a special long-range order (quasiperiodicity) showing diffraction symmetry different from ordinal crystals such as icosahedral symmetry and 12-fold symmetry. In order to clarify the physical properties originated from such structural specificity, we have conducted research centered on new-substance search. Theoretically, the possibility of a new dodecagonal quasicrystal containing Yb was pointed out using "high-dimensional analysis", and experimentally the first superconductivity (Zn-Mg-Al alloy) in a quasicrystal as well as formation of a new quasicrystal in Zn-Au alloys were discovered. Furthermore, we found phase separation (Cu-Ga-Sc alloy) with a difference in cluster structure, and a difference in electronic state of Yb (Au-Ge-Yb alloy) due to similar difference in the approximant crystals.
It is thought that these have brought us one step closer to the goal of “clarifying the physical properties inherent in quasicrystals”.
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| Academic Significance and Societal Importance of the Research Achievements |
歴史の区分として，しばしば石器時代，青銅時代，鉄器時代，シリコン時代などを用いますが，これらは全て”結晶の時代”と言うことができます．ところが最近，専門家の間では準結晶と呼ばれる物質群が注目されています．準結晶は，アルミニウム，銅，鉄など，金属の合金として形成しますが，結晶ともアモルファスとも異なる「特別の規則」に従って原子が並んでいるため，従来の金属材料とは異なる「未来材料になりうるような性質」を持っています．ここでは，新物質探索を軸として，そのような準結晶についての基礎研究を行いました．
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