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Electronic Structure of AgPbmSbTem+2 Compounds – Implications on Thermoelectric Properties

Published online by Cambridge University Press:  01 February 2011

Khang Hoang
Affiliation:
hoang@pa.msu.edu, Michigan State University, Department of Physics and Astronomy, East Lansing, MI, 48824-2320, United States, 517 355 9200 x2348
S. D. Mahanti*
Affiliation:
mahanti@pa.msu.edu, Michigan State University, Department of Physics and Astronomy, United States
J. Androulakis
Affiliation:
androula@chemistry.msu.edu, Michigan State University, Department of Chemistry, United States
M. G. Kanatzidis
Affiliation:
kanatzidis@chemistry.msu.edu, Michigan State University, Department of Chemistry, United States
*
* Corresponding author. Electronic mail: mahanti@pa.msu.edu
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Abstract

Novel quaternary compounds AgPbmSbTem+2 (LAST-m) with different m values have been synthesized recently and some of these compounds show promising thermoelectric properties at high temperatures. The two end members of the series, PbTe (m=∞) and AgSbTe2 (m=0), are also known to be good thermoelectrics. In this paper, we discuss the results of ab initio electronic structure calculations for these two end members and for LAST-2 and LAST-14 to see how the electronic structure near the chemical potential μ evolves with m. Whereas PbTe and LAST-14 are narrow band gap semiconductors, the other two compounds show pseudo-gap structure. Even in the absence of a true gap, the rapidly varying density of states (DOS) near μ may be conducive to large Seebeck coefficient in LAST-2 and AgSbTe2.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

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References

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