Structural evolution of high-performance Mn-alloyed thermoelectric materials: a case study of SnTe
Article
Article Title | Structural evolution of high-performance Mn-alloyed thermoelectric materials: a case study of SnTe |
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ERA Journal ID | 3432 |
Article Category | Article |
Authors | Sun, Qiang (Author), Chen, Zhi-Yu (Author), Li, Meng (Author), Shi, Xiao-Lei (Author), Xu, Sheng-Duo (Author), Yin, Yu (Author), Dargusch, Matthew (Author), Zou, Jin (Author), Ang, Ran (Author) and Chen, Zhi-Gang (Author) |
Journal Title | Small |
Article Number | 2100525 |
Number of Pages | 10 |
Year | 2021 |
Publisher | John Wiley & Sons |
Place of Publication | Germany |
ISSN | 1613-6810 |
1613-6829 | |
Digital Object Identifier (DOI) | https://doi.org/10.1002/smll.202100525 |
Web Address (URL) | https://onlinelibrary.wiley.com/doi/10.1002/smll.202100525 |
Abstract | Mn alloying in thermoelectrics is a long-standing strategy for enhancing their figure-of-merit through optimizing electronic transport properties by band convergence, valley perturbation, or spin-orbital coupling. By contrast, mechanisms by which Mn contributes to suppressing thermal transports, namely thermal conductivity, is still ambiguous. A few precedent studies indicate that Mn introduces a series of hierarchical defects from the nano- to meso-scale, leading to effective phonon scattering scoping a wide frequency spectrum. Due to insufficient insights at the atomic level, the theory remains as phenomenological and cannot be used to quantitatively predict the thermal conductivity of Mn-alloyed thermoelectrics. Herein, by choosing the SnTe as a case study, aberration-corrected transmission electron microscopy (TEM)/scanning transmission electron microscopy (STEM) to characterize the lattice complexity of Sn1.02−xMnxTe is employed. Mn as a “dynamic” dopant that plays an important role in SnTe with respect to different alloying levels or post treatments is revealed. The results indicate that Mn precipitates at x = 0.08 prior to reaching solubility (≈10 mol%), and then splits into MnSn substitution and γ-MnTe hetero-phases via mechanical alloying. Understanding such unique crystallography evolution, combined with a modified Debye-Callaway model, is critical in explaining the decreased thermal conductivity of Sn1.02−xMnxTe with rational phonon scattering pathways, which should be applicable for other thermoelectric systems. |
ANZSRC Field of Research 2020 | 401605. Functional materials |
Public Notes | © 2021 Wiley-VCH GmbH. |
Byline Affiliations | University of Queensland |
Sichuan University, China | |
Centre for Future Materials | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q658y/structural-evolution-of-high-performance-mn-alloyed-thermoelectric-materials-a-case-study-of-snte
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