| Project/Area Number |
26800184
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Condensed matter physics II
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| Research Institution | Niigata University |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2016-03-31
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| Project Status |
Completed (Fiscal Year 2015)
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| Budget Amount *help |
¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2014: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
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| Keywords | マルチバンド超伝導 / 鉄系超伝導体 / 電気四極子 / 超音波計測 / 弾性定数 / 超音波吸収係数 / 鉄系高温超伝導 / 一軸圧 |
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| Outline of Final Research Achievements |
We have measured the ultrasonic attenuation coefficients of iron-based superconductors Ba(Fe1-xCox)2As2 and A-15 Superconductor V3Si with multiband structure. Ultrasonic attenuation coefficients show divergent increase with divergent softening of elastic constants toward the structural phase transition. Because this behavior indicates a critical slowing down phenomenon of quadrupole, the structural phase transition is a ferro quadrupole phase transition. On the other hand, Ultrasonic attenuation coefficient only shows divergent increase toward the superconducting transition. We performed analysis and calculation to focus the rotation induced by transverse ultrasound. We clarified that two conduction electrons form a hexadecapole to create a bound state and the critical slowing down occurs, which shows that the fluctuation of the hexadecapole increases divergently.
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