NMR Observation of Rattling Phonons in the Pyrochlore SuperconductorKOs2O6
| Autor: | R. Kaido, Minoru Yoshida, Yuji Muraoka, Shigeki Yonezawa, Koya Arai, Zenji Hiroi, Masashi Takigawa |
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| Rok vydání: | 2007 |
| Předmět: |
Superconductivity
Materials science Condensed matter physics Phonon Anharmonicity Pyrochlore Oxide General Physics and Astronomy engineering.material Coupling (physics) chemistry.chemical_compound chemistry Condensed Matter::Superconductivity engineering Low-frequency oscillation Electric field gradient |
| Zdroj: | Physical Review Letters. 98 |
| ISSN: | 1079-7114 0031-9007 |
| DOI: | 10.1103/physrevlett.98.197002 |
| Popis: | We report nuclear magnetic resonance studies on the beta-pyrochlore oxide superconductor KOs2O6. The nuclear relaxation at the K sites is entirely caused by fluctuations of the electric field gradient, which we ascribe to highly anharmonic low frequency oscillation (rattling) of K ions. A phenomenological analysis shows a crossover from overdamped to underdamped behavior of the rattling phonons with decreasing temperature and its sudden sharpening below the superconducting transition temperature T(c). Suppression of the Hebel-Slichter peak in the relaxation rate at the O sites below T(c) also indicates strong electron-phonon coupling. |
| Databáze: | OpenAIRE |
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