TY - JOUR
T1 - Optimization of thermoelectric properties of type-VIII clathrate Ba 8Ga16Sn30 by carrier tuning
AU - Saiga, Y.
AU - Suekuni, K.
AU - Deng, S. K.
AU - Yamamoto, T.
AU - Kono, Y.
AU - Ohya, N.
AU - Takabatake, T.
N1 - Funding Information:
We thank Y. Shibata for the EPMA performed at Natural Science Center for Basic Research and Development, Hiroshima University. We are grateful to T. Takeuchi for the generous use of MMR Measurement System for the measurement of Seebeck coefficient. This work was supported by a NEDO , grant no. 09002139-0 and Grant-in-Aid for Scientific Research from MEXT of Japan , grants no. 1824032 , no. 19051011 , and no. 20102004 .
PY - 2010/9/24
Y1 - 2010/9/24
N2 - Single crystals of type-VIII clathrate Ba8Ga16Sn 30 (BGS) with p- and n-type carriers were grown from Ga flux and Sn flux, respectively. With the increase of the initial flux amount, both the electrical resistivity ρ and the absolute value of the Seebeck coefficient α are decreased, indicative of effective carrier doping. In the optimally doped samples, the dimensionless thermoelectric figure of merit ZT has the maximum values of 1.0 and 0.9 at 450 K for p-and n-type samples, respectively. In aiming at further increase of the ZT value, Sb was substituted for Sn in BGS. It is found that the Ga content in the crystals unexpectedly increases with the increase of Sb content and thus the crystal composition is described as Ba 8Ga16+xSn30-x-ySby (x < 0.9, y < 0.9). The ZT value for the p-type sample with x = y = 0.7 has the maximum of 1.0 at around 480 K.
AB - Single crystals of type-VIII clathrate Ba8Ga16Sn 30 (BGS) with p- and n-type carriers were grown from Ga flux and Sn flux, respectively. With the increase of the initial flux amount, both the electrical resistivity ρ and the absolute value of the Seebeck coefficient α are decreased, indicative of effective carrier doping. In the optimally doped samples, the dimensionless thermoelectric figure of merit ZT has the maximum values of 1.0 and 0.9 at 450 K for p-and n-type samples, respectively. In aiming at further increase of the ZT value, Sb was substituted for Sn in BGS. It is found that the Ga content in the crystals unexpectedly increases with the increase of Sb content and thus the crystal composition is described as Ba 8Ga16+xSn30-x-ySby (x < 0.9, y < 0.9). The ZT value for the p-type sample with x = y = 0.7 has the maximum of 1.0 at around 480 K.
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U2 - 10.1016/j.jallcom.2010.07.121
DO - 10.1016/j.jallcom.2010.07.121
M3 - Article
AN - SCOPUS:77956617546
VL - 507
SP - 1
EP - 5
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
IS - 1
ER -