| DOI | Resolve DOI: https://doi.org/10.1088/1742-6596/340/1/012074 |
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| Author | Search for: Yamani, Z.1; Search for: Ryan, D. H.; Search for: Cadogan, J. M.; Search for: Canepa, F.; Search for: Palenzona, A.; Search for: Orecchini, Andrea |
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| Affiliation | - National Research Council of Canada. NRC Canadian Neutron Beam Centre
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| Format | Text, Article |
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| Conference | 5th European Conference on Neutron Scattering (ECNS 2011), July 17-22, 2011, Prague, Czech Republic |
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| Abstract | While the high transition temperatures suggest that the conventional BCS phononmediated mechanism may not provide the main pairing mechanism in the recently discovered RFeAsO1−xFx (1111-type) superconductors, there is, as yet, no consensus, despite extensive experimental and theoretical study. We report here the results of an inelastic neutron scattering investigation of an overdoped polycrystalline sample of LaFeAsO1−xFx with x = 0.15 (Tc = 26 K). Four excitation peaks were observed at 13.6±1.5, 24.2±0.8, 32.2±0.5, and 41.4±1.0 meV. They were identified as phonon modes based on their wavevector and temperature dependence. The peak positions agree well with first-principles calculations of phonon density of states as well as experimental data on both the insulating parent and optimally doped LaFeAsO1−xFx compounds. No evidence for the presence of a resonance mode was found. We found that the phonon density of states of the x = 0.15 sample remains unchanged below Tc and is similar to samples with other fluorine concentrations. This suggests that a standard electron-phonon pairing mechanism cannot explain the high transition temperatures observed in these materials. |
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| Publication date | 2012 |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 20140155 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | cbcc3ce9-dec6-43ab-8f03-77e90fe33b16 |
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| Record created | 2012-06-14 |
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| Record modified | 2020-04-21 |
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