Abstract
We report studies of 117,119Sn and 69,71Ga nuclear magnetic resonance (NMR) to investigate electron-phonon interactions due to the off-center rattling of Ba atoms in the semi-metallic type-I Ba 8Ga16Sn30clathrate with n-type charge carriers in the temperature range of 0.4-200 K. The Ga NMR spin-lattice relaxation rate has an anomalous enhancement at approximately 10 K, indicating that the Ba atoms exhibit thermal rattling motion in an anharmonic potential. From calculations using a two-phonon Raman process model for a one-dimensional anharmonic Hamiltonian within a quasi-harmonic approximation, significant broadening of the phonon lifetime and softening of the phonon frequency are found to be essential to reproduce the temperature dependence of the NMR spin-lattice relaxation rate. The characteristic energy of the renormalized phonon frequency w r≈ 21K was obtained for the rattling state, in agreement with the values estimated by heat capacity analysis and other techniques. These results point to strong coupling of the rattling phonon to conduction electrons in semimetallic type-I Ba8Ga16Sn30.
| Original language | English |
|---|---|
| Article number | 114603 |
| Journal | journal of the physical society of japan |
| Volume | 82 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Nov 1 2013 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
Cite this
Strong coupling of rattling phonon to conduction electrons in semimetallic type-I clathrate Ba8Ga16Sn30 . / Tou, Hideki; Sonoda, Kanto; Furumoto, Kazuya; Kotegawa, Hisashi; Suekuni, Koichiro; Avila, Marcos A.; Takabatake, Toshiro.
In: journal of the physical society of japan, Vol. 82, No. 11, 114603, 01.11.2013.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Strong coupling of rattling phonon to conduction electrons in semimetallic type-I clathrate Ba8Ga16Sn30
AU - Tou, Hideki
AU - Sonoda, Kanto
AU - Furumoto, Kazuya
AU - Kotegawa, Hisashi
AU - Suekuni, Koichiro
AU - Avila, Marcos A.
AU - Takabatake, Toshiro
PY - 2013/11/1
Y1 - 2013/11/1
N2 - We report studies of 117,119Sn and 69,71Ga nuclear magnetic resonance (NMR) to investigate electron-phonon interactions due to the off-center rattling of Ba atoms in the semi-metallic type-I Ba 8Ga16Sn30clathrate with n-type charge carriers in the temperature range of 0.4-200 K. The Ga NMR spin-lattice relaxation rate has an anomalous enhancement at approximately 10 K, indicating that the Ba atoms exhibit thermal rattling motion in an anharmonic potential. From calculations using a two-phonon Raman process model for a one-dimensional anharmonic Hamiltonian within a quasi-harmonic approximation, significant broadening of the phonon lifetime and softening of the phonon frequency are found to be essential to reproduce the temperature dependence of the NMR spin-lattice relaxation rate. The characteristic energy of the renormalized phonon frequency w r≈ 21K was obtained for the rattling state, in agreement with the values estimated by heat capacity analysis and other techniques. These results point to strong coupling of the rattling phonon to conduction electrons in semimetallic type-I Ba8Ga16Sn30.
AB - We report studies of 117,119Sn and 69,71Ga nuclear magnetic resonance (NMR) to investigate electron-phonon interactions due to the off-center rattling of Ba atoms in the semi-metallic type-I Ba 8Ga16Sn30clathrate with n-type charge carriers in the temperature range of 0.4-200 K. The Ga NMR spin-lattice relaxation rate has an anomalous enhancement at approximately 10 K, indicating that the Ba atoms exhibit thermal rattling motion in an anharmonic potential. From calculations using a two-phonon Raman process model for a one-dimensional anharmonic Hamiltonian within a quasi-harmonic approximation, significant broadening of the phonon lifetime and softening of the phonon frequency are found to be essential to reproduce the temperature dependence of the NMR spin-lattice relaxation rate. The characteristic energy of the renormalized phonon frequency w r≈ 21K was obtained for the rattling state, in agreement with the values estimated by heat capacity analysis and other techniques. These results point to strong coupling of the rattling phonon to conduction electrons in semimetallic type-I Ba8Ga16Sn30.
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U2 - 10.7566/JPSJ.82.114603
DO - 10.7566/JPSJ.82.114603
M3 - Article
AN - SCOPUS:84887106542
VL - 82
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 11
M1 - 114603
ER -