Thermoelectric and transport properties of sintered n-type K{sub 8}Ba{sub 16}Ga{sub 40}Sn{sub 96} with type-II clathrate structure

Journal Article · Mon Jul 14 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4889822· OSTI ID:22308449

Koda, Shota; Kishimoto, Kengo; Asada, Hironori; Koyanagi, Tsuyoshi ^[1]; Akai, Koji ^[2]

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1. Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube, Yamaguchi 755-8611 (Japan)
2. Media and Information Technology Center, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8511 (Japan)

This clathrate had a maximum dimensionless figure-of-merit, ZT, of 0.93 at 637 K, which was slightly higher than that of 0.83 for the sintered type-VIII clathrate Ba{sub 8}Ga{sub 16}Sn{sub 30}. We investigated the high-temperature thermoelectric properties, transport properties, electronic structures, and thermal stabilities of the clathrates. The type-II clathrate was found to be superior to the type-VIII clathrate as a thermoelectric material; it had a high thermal stability and melting point, 859 K, high mobility, 141 cm{sup 2}V{sup −1}s{sup −1} at 300 K, because of its low inertial mass, and low high-temperature lattice thermal conductivity, approximately 4 mW cm{sup −1}K{sup −1}, resulting from a larger unit cell and weaker bipolar thermal conduction. We discuss these properties in terms of the electronic structure and the differences between the two types of clathrate.

• OSTI ID: 22308449
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
APPROXIMATIONS
BARIUM COMPOUNDS
CARRIER MOBILITY
CLATHRATES
ELECTRIC CONDUCTIVITY
ELECTRONIC STRUCTURE
GALLIUM COMPOUNDS
MASS
MELTING POINTS
PERFORMANCE
STABILITY
TEMPERATURE RANGE 0400-1000 K
THERMAL CONDUCTION
THERMAL CONDUCTIVITY
THERMOELECTRIC MATERIALS
THERMOELECTRIC PROPERTIES
TIN COMPOUNDS