Mechanical alloying boosted SnTe thermoelectrics

Chen, Zhiyu and Sun, Qiang and Zhang, Fujie and Mao, Jianjun and Chen, Yue and Li, Meng and Chen, Zhi-Gang ORCID: https://orcid.org/0000-0002-9309-7993 and Ang, Ran (2021) Mechanical alloying boosted SnTe thermoelectrics. Materials Today Physics, 17:100340. pp. 1-8.


Abstract

The well converged transporting valence bands in SnTe-MnTe alloys ensures a superior electronic performance, while their thermal transport properties still need to be further optimized for higher thermoelectric performance. Herein, the mechanical alloying is utilized to fabricate the SnTe-15%MnTe-2%Bi alloys, leading to a remarkable reduction of grain size as well as the formation of dense dislocations. Unexpectedly, the solubility of MnTe is reduced to ∼6% by mechanical alloying at room temperature, inducing an enhanced phonon scattering from nanoprecipitates. These full-scale hierarchical microstructures effectively decrease the lattice thermal conductivity of SnTe-15%MnTe-2%Bi to ∼0.5 W m−1 K−1 at 850 K. In addition, the increased vacancy formation energy triggers a reduction in carrier concentration (∼3 × 1019 cm−3) due to the decreased MnTe content in matrix. Moreover, the energy filtering effect through precipitate-matrix interface enables an improvement in Seebeck coefficient. Accordingly, the figure of merit of SnTe-15%MnTe-2%Bi is dramatically increased to ∼1.5 at 850 K by mechanical alloying. This work clearly demonstrates that mechanical alloying changes the composition and microstructure of materials, which significantly affect the thermoelectric transport properties, enabling an obvious performance enhancement.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Date Deposited: 24 May 2022 03:26
Last Modified: 31 May 2022 02:13
Uncontrolled Keywords: Thermoelectric materials; SnTe; Hierarchical microstructures; Interfacial engineering; Mechanical alloying
Fields of Research (2008): 10 Technology > 1007 Nanotechnology > 100708 Nanomaterials
09 Engineering > 0912 Materials Engineering > 091203 Compound Semiconductors
09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Fields of Research (2020): 40 ENGINEERING > 4016 Materials engineering > 401603 Compound semiconductors
40 ENGINEERING > 4016 Materials engineering > 401605 Functional materials
34 CHEMICAL SCIENCES > 3403 Macromolecular and materials chemistry > 340301 Inorganic materials (incl. nanomaterials)
40 ENGINEERING > 4018 Nanotechnology > 401807 Nanomaterials
Identification Number or DOI: https://doi.org/10.1016/j.mtphys.2021.100340
URI: http://eprints.usq.edu.au/id/eprint/48498

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