TY - GEN
T1 - Thermal conductivity and guest vibration in cage-size controlled Ba 8in16Ge30-xMx (M=Si, Sn)
AU - Suekuni, K.
AU - Yamamoto, S.
AU - Avila, M. A.
AU - Takabatake, T.
PY - 2007/12/1
Y1 - 2007/12/1
N2 - We report thermal and transport measurements on single crystalline samples of Ba8In16Ge30-xMx (M=Si, Sn, x ≤, 2.2), which crystallize in the type-I clathrate structure. On going from Mx = Si 1.6 to Mx = Sn2.2, the lattice parameter increases by 1% from 11.20 to 11.30 Å. All the samples show semi-metallic behavior with n-type majority carries. The analysis of the specific heat indicates that the local vibration energy of the Ba guests in the tetrakaidecahedron decreases from 39 to 35 K with the increase of the lattice parameter. Concomitantly, the lattice thermal conductivity is largely suppressed and that for Mx = Sn2.2 shows a glasslike temperature dependence. The phonon scattering is greatly increased as a consequence of the strengthened coupling between guest vibration and the cage's acoustic phonon.
AB - We report thermal and transport measurements on single crystalline samples of Ba8In16Ge30-xMx (M=Si, Sn, x ≤, 2.2), which crystallize in the type-I clathrate structure. On going from Mx = Si 1.6 to Mx = Sn2.2, the lattice parameter increases by 1% from 11.20 to 11.30 Å. All the samples show semi-metallic behavior with n-type majority carries. The analysis of the specific heat indicates that the local vibration energy of the Ba guests in the tetrakaidecahedron decreases from 39 to 35 K with the increase of the lattice parameter. Concomitantly, the lattice thermal conductivity is largely suppressed and that for Mx = Sn2.2 shows a glasslike temperature dependence. The phonon scattering is greatly increased as a consequence of the strengthened coupling between guest vibration and the cage's acoustic phonon.
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U2 - 10.1109/ICT.2007.4569467
DO - 10.1109/ICT.2007.4569467
M3 - Conference contribution
AN - SCOPUS:51849150845
SN - 9781424422623
T3 - International Conference on Thermoelectrics, ICT, Proceedings
SP - 234
EP - 236
BT - Proceedings ICT'07 - 26th International Conference on Thermoelectrics
T2 - ICT'07 - 26th International Conference on Thermoelectrics
Y2 - 3 June 2007 through 7 June 2007
ER -