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Meltspun Ba8Ga16−xGe30+x clathrates

Published online by Cambridge University Press:  05 August 2011

S. Laumann ,
M. Ikeda ,
H. Sassik ,
A. Prokofiev  and
S. Paschen
S. Laumann
Affiliation:
Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria
M. Ikeda
Affiliation:
Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria
H. Sassik
Affiliation:
Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria
A. Prokofiev
Affiliation:
Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria
S. Paschen*
Affiliation:
Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Ba8Ga16−xGe30+x is the clathrate with the highest thermoelectric figure of merit known to date. However, no p-type material could be obtained by conventional synthesis from the melt. Here we show that the time and cost-effective melt spinning technique can produce Ba8Ga16−xGe30+x in a metastable state, where x can be varied continuously from negative to positive values, resulting in both p- and n-type materials. The quenched phases were characterized by x-ray powder diffraction and transmission electron microscopy. It was surprising that they were perfectly crystalline, with large grain sizes of the order of a micrometer. Temperature dependent measurements of the electrical resistivity, Hall effect, thermopower, and thermal conductivity are presented and discussed in terms of a two-band model.

Keywords

clathratesthermoelectricrapid solidification
Type
Articles
Information
Journal of Materials Research , Volume 26 , Issue 15: Focus Issue: Advances in Thermoelectric Materials , 14 August 2011 , pp. 1861 - 1865
Copyright
Copyright © Materials Research Society 2011

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References

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