TY - JOUR
T1 - NMR observation of rattling phonons in the pyrochlore superconductor KOs2O6
AU - Yoshida, M.
AU - Arai, K.
AU - Kaido, R.
AU - Takigawa, M.
AU - Yonezawa, S.
AU - Muraoka, Y.
AU - Hiroi, Z.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2007/5/8
Y1 - 2007/5/8
N2 - We report nuclear magnetic resonance studies on the β-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 Tc. Suppression of the Hebel-Slichter peak in the relaxation rate at the O sites below Tc also indicates strong electron-phonon coupling.
AB - We report nuclear magnetic resonance studies on the β-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 Tc. Suppression of the Hebel-Slichter peak in the relaxation rate at the O sites below Tc also indicates strong electron-phonon coupling.
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U2 - 10.1103/PhysRevLett.98.197002
DO - 10.1103/PhysRevLett.98.197002
M3 - Article
AN - SCOPUS:34547341208
VL - 98
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 19
M1 - 197002
ER -