2017 Fiscal Year Final Research Report
Spin dynamics of iron-based superconductors studied by inelastic pulse neutron scattering -origin of localize and itinerant nature-
| Project/Area Number |
16K17750
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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 | Okayama University |
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Principal Investigator |
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| Project Period (FY) |
2016-04-01 – 2018-03-31
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| Keywords | 鉄系超伝導体 / パルス中性子 / 磁気励起 |
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| Outline of Final Research Achievements |
Understanding the overall features of magnetic excitation is essential for clarifying the mechanism of Cooper pair formation in iron-based superconductors. Here we report a study on the spin fluctuations of the hole-overdoped iron-based superconductors Ba1-xKxFe2As2 (x = 0.5 and 1.0; Tc = 36 K and 3.4 K, respectively) over the entire Brillouin zone using inelastic neutron scattering. We found that their spin spectra consist of spin wave and chimney-like dispersions. The chimneylike dispersion can be attributed to the itinerant character of magnetism. The band width of the spin wave-like dispersion is almost constant from the non-doped to optimum-doped region, which is followed by a large reduction in the overdoped region. This suggests that the superconductivity is suppressed by the reduction of magnetic exchange couplings, indicating a strong relationship between magnetism and superconductivity in iron-based superconductors.
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| Free Research Field |
超伝導、中性子回折
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