Thermoelectric properties of n-type half-Heusler NbCoSn with heavy-element Pt substitution
Serrano-Sanchez F, Luo T, Yu J, Xie W, Le C, Auffermann G, Weidenkaff A, Zhu T, Zhao X, Alonso JA, Gault B, Felser C, Fu C (2020)
Publication Type: Journal article
Publication year: 2020
Journal
Book Volume: 8
Pages Range: 14822-14828
Journal Issue: 29
DOI: 10.1039/d0ta04644b
Abstract
Half-Heusler compounds with a valence electron count of 18, including ZrNiSn, ZrCoSb, and NbFeSb, are good thermoelectric materials owing to favorable electronic structures. Previous computational studies had predicted a high electrical power factor in another half-Heusler compound NbCoSn, but it has not been extensively investigated experimentally. Herein, the synthesis, structural characterization, and thermoelectric properties of the heavy-element Pt-substituted NbCoSn compounds are reported. Pt is found to be an effective substitute enabling the optimization of electrical power factor and simultaneously leading to a strong point defect scattering of phonons and the suppression of lattice thermal conductivity. Post-annealing significantly improves the carrier mobility, which is ascribed to the decreased grain boundary scattering of electrons. As a result, a maximum power factor of ∼3.4 mW m-1 K-2 is obtained at 600 K. In conjunction with the reduced lattice thermal conductivity, a maximum figure of merit zT of ∼0.6 is achieved at 773 K for the post-annealed NbCo0.95Pt0.05Sn, an increase of 100% compared to that of NbCoSn. This work highlights the important roles that the dopant element and microstructure play in the thermoelectric properties of half-Heusler compounds.
Involved external institutions
Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids
Germany (DE)
Technische Universität Darmstadt
Germany (DE)
Max-Planck-Institut für Eisenforschung GmbH (MPIE) / Max Planck Institute for Iron Research
Germany (DE)
Zhejiang University / Chekiang University / 浙江大学
China (CN)
Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC)
Spain (ES)
Germany (DE)
Technische Universität Darmstadt
Germany (DE)
Max-Planck-Institut für Eisenforschung GmbH (MPIE) / Max Planck Institute for Iron Research
Germany (DE)
Zhejiang University / Chekiang University / 浙江大学
China (CN)
Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC)
Spain (ES)
How to cite
APA:
Serrano-Sanchez, F., Luo, T., Yu, J., Xie, W., Le, C., Auffermann, G.,... Fu, C. (2020). Thermoelectric properties of n-type half-Heusler NbCoSn with heavy-element Pt substitution. Journal of Materials Chemistry A, 8(29), 14822-14828. https://doi.org/10.1039/d0ta04644b
MLA:
Serrano-Sanchez, Federico, et al. "Thermoelectric properties of n-type half-Heusler NbCoSn with heavy-element Pt substitution." Journal of Materials Chemistry A 8.29 (2020): 14822-14828.
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