May, 2007
NMR observation of rattling phonons in the pyrochlore superconductor KOs2O6
PHYSICAL REVIEW LETTERS
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- Volume
- 98
- Number
- 19
- First page
- 197002
- Last page
- Language
- English
- Publishing type
- Research paper (scientific journal)
- DOI
- 10.1103/PhysRevLett.98.197002
- Publisher
- AMERICAN PHYSICAL SOC
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.
- Link information
- ID information
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- DOI : 10.1103/PhysRevLett.98.197002
- ISSN : 0031-9007
- Web of Science ID : WOS:000246413200046