Zintl-phase compounds with SnSb4 tetrahedral anions: electronic structure and thermoelectric properties

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.81.075117· OSTI ID:979319

Zhang, Lijun ^[1]; Du, Mao-Hua ^[1]; Singh, David J ^[1]

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1. ORNL

We report the investigation of Zintl-phase Na(K){sub 8}SnSb{sub 4} and related compounds that contain SnSb{sub 4} tetrahedral anions using first principles electronic structure, Boltzmann transport, and density functional phonon calculations. We find that these compounds are narrow-gap semiconductors and there is a combination of heavy and light bands at valence band edge, which may lead to a combination of high thermopower and reasonable conductivity. High values of the thermopower are found for p-type doping within the Boltzmann transport theory. Furthermore, these materials are expected to have low thermal conductivity due to their structures that consist of a network of weakly coupled SnSb{sub 4} clusters, which leads to low phonon frequencies. In particular, we find low-frequency optical phonons that should effectively scatter the heat-carrying acoustic phonons. These results are discussed in terms of the structure, which consists of anionic clusters. Based on the results, it is suggested that such compounds may represent a useful paradigm for finding new thermoelectric materials.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: EE USDOE - Office of Energy Efficiency and Renewable Energy (EE); SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 979319
• Journal Information: Physical Review B, Journal Name: Physical Review B Journal Issue: 7 Vol. 81; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACOUSTICS
ANIONS
ELECTRONIC STRUCTURE
FUNCTIONALS
PHONONS
THERMAL CONDUCTIVITY
THERMOELECTRIC MATERIALS
THERMOELECTRIC PROPERTIES
TRANSPORT
TRANSPORT THEORY
VALENCE