Effects of Ga content on thermoelectric properties of P-type Ba8Ga16+xZn3Ge27−x type-I clathrates
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P-type Ba8Ga16+xZn3Ge27−x (x = 0.1, 0.2, 0.3, and 0.4) type-I clathrates were synthesized by combining solid-state reaction with spark plasma sintering (SPS) technology. The effects of slight increase of Ga content on thermoelectric properties have been investigated. The results show that at room temperature the carrier concentration Np of p-type Ba8Ga16+xZn3Ge27−x clathrates increases remarkably compared with that of Ba8Ga16Zn3Ge27 compound, which results in the increases of electrical conductivity although carrier mobility μH slightly decreases. The thermal conductivity κ of all samples increases with the increase of Ga content. Ba8Ga16.2Zn3Ge26.8 compound exhibits the highest ZT value of 0.43 at 700 K, which is increased by 13% compared with that of Ba8Ga16Zn3Ge27 compound.
KeywordsCarrier Concentration Clathrate Spark Plasma Sinter Seebeck Coefficient Lattice Thermal Conductivity
This work is sponsored by the National Basic Research Program of China (Grant Nos. 2007CB607501 and 2007CB607503) and Yunnan Natural Science Fund (Grand No. 2008CD114).
- 17.Nolas GS, Slack GA, Schujman SB (2001) In: Tritt TM (ed) Semiconductors and semimetals. Academic Press Inc., New York, p 291Google Scholar
- 18.Kishimoto K, Akai K, Muraoka N, Koyanagi T, Matsuura M (2006) Appl Phys Lett 891:72106Google Scholar
- 25.Uher C, Yang J, Hu S (1999) Mater Res Soc Symp Proc 54:247Google Scholar