Thermoelectric Material SnPb2Bi2S6: The 4,4L Member of Lillianite Homologous Series with Low Lattice Thermal Conductivity
| Autor: | Chris Wolverton, Li-Dong Zhao, Jingpeng Li, Jing Zhao, Shiqiang Hao, Yiming Zhou, Tianyan Zhang |
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| Rok vydání: | 2018 |
| Předmět: |
010405 organic chemistry
Phonon Crystal structure 010402 general chemistry Thermoelectric materials 01 natural sciences 0104 chemical sciences Inorganic Chemistry symbols.namesake Homologous series chemistry.chemical_compound Crystallography Thermal conductivity chemistry symbols Orthorhombic crystal system Thermal stability Physical and Theoretical Chemistry Debye model |
| Zdroj: | Inorganic Chemistry. 58:1339-1348 |
| ISSN: | 1520-510X 0020-1669 |
| Popis: | Although the binary sulfides Bi2S3, PbS, and SnS have attracted extensive interest as thermoelectric materials, no quaternary sulfides containing Sn/Pb/Bi/S elements have been reported. Herein, we report the synthesis of a new quaternary sulfide, SnPb2Bi2S6, which crystallizes in the orthorhombic space group Pnma with unit cell parameters of a = 20.5458(12) A, b = 4.0925(4) A, c = 13.3219(10) A. SnPb2Bi2S6 has a lillianite-type crystal structure consisting of two alternately aligned NaCl-type structural motifs separated by a mirror plane of PbS7 monocapped trigonal prisms. In the lillianite homologous series, SnPb2Bi2S6 can be classified as 4,4L, where the superscripted numbers indicate the maximum numbers of edge-sharing octahedra in the two adjacent NaCl-shaped slabs along the diagonal direction. The obtained SnPb2Bi2S6 phase exhibited good thermal stability up to 1000 K and n-type degenerate semiconducting behavior, with a power factor of 3.7 μW cm-1 K-2 at 773 K. Notably, this compound exhibited a very low lattice thermal conductivity of 0.69-0.92 W m-1 K-1 at 300-1000 K. Theoretical calculations revealed that the low thermal conductivity is caused by the complex crystal structure and the related elastic properties of a low Debye temperature, low phonon velocity, and large Gruneisen parameters. A reasonable figure of merit (ZT) of ∼0.3 was obtained at 770 K. |
| Databáze: | OpenAIRE |
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