Temperature‐dependent thermal properties of phase‐pure polycrystalline ternary chalcogenides Cu4Bi4S9and Cu4Bi4Se9are reported. The structure and bonding in these materials result in very low thermal conductivity values (<0.8 W m−1 K−1at room temperature) for both materials. The lattice contribution, Debye temperatures, and Sommerfeld coefficient are obtained from low‐temperature heat capacity data that also indicate very small electronic contributions to the heat capacity for these materials. This study aids in the identification of new nontoxic, earth‐abundant resistive ternary chalcogenide materials with low thermal conductivity for potential thermal barrier coating and rewriteable storage applications.
Structural and thermal properties of ultralow thermal conductivity Ba 3 Cu 2 Sn 3 Se 10
The thermal properties of Ba 3 Cu 2 Sn 3 Se 10 were investigated by measurement of the thermal conductivity and heat capacity. The chemical bonding in this diamagnetic material was investigated using structural data from Rietveld refinement and calculated electron localization. This quaternary chalcogenide is monoclinic ( P 2 1 / c ), has a large unit cell with 72 atoms in the primitive cell, and a high local coordination environment. The Debye temperature (162 K) and average speed of sound (1666 m s −1 ) are relatively low with a very small electronic contribution to the heat capacity. Ultralow thermal conductivity (0.46 W m −1 K −1 at room temperature) is attributed to the relatively weak chemical bonding and intrinsic anharmonicity, in addition to a large unit cell. This work is part of the continuing effort to explore quaternary chalcogenides with intrinsically low thermal conductivity and identify the features that result in a low thermal conductivity.
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- Award ID(s):
- 1748188
- NSF-PAR ID:
- 10329576
- Date Published:
- Journal Name:
- Dalton Transactions
- Volume:
- 51
- Issue:
- 16
- ISSN:
- 1477-9226
- Page Range / eLocation ID:
- 6220 to 6225
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d2dt00309k
