The Effects of Excess Co on the Phase Composition and Thermoelectric Properties of Half-Heusler NbCoSb
Abstract
NbCoSb with nominal 19 valence electrons, and is supposed to be metallic, has recently been reported to also exhibit the thermoelectric properties of a heavily doped n-type semiconductor. In this study, we prepared Co-rich NbCo 1+xSb samples (x = 0, 0.2, 0.3, 0.4, 0.5), and their phase compositions, microstructures and thermoelectric properties were investigated. The Seebeck coefficient increased a great deal with increasing x, due to decreasing carrier concentration, and the total thermal conductivity reduced mainly because of declining κ e. Finally, a peak thermoelectric figure of merit, ZT, was about 0.46 for NbCo 1.3Sb at 973 K. This enhancement was mainly attributed to the reduction of electric thermal conductivity and the increase of Seebeck coefficient. The excess Co had effects on the carrier concentration, deformation potential E def and DOS effective mass m *. Adding an excessive amount of Co leads to a very high E def, which was detrimental for transport characteristics.
- Authors:
-
[1];
- Xihua Univ., Chemgdu (China). Key Lab. of Fluid and Power Machinery of Ministry of Education, School of Materials Science & Engineering
- Leibniz Inst. for Solid State and Materials Research (IFW), Dresden (Germany). Inst. for Metallic Materials
- Univ. of Houston, TX (United States). Dept. of Physics and Texas Center for Superconductivity
- Publication Date:
- Research Org.:
- Energy Frontier Research Centers (EFRC) (United States). Solid-State Solar-Thermal Energy Conversion Center (S3TEC); Massachusetts Inst. of Tech., Cambridge, MA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- OSTI Identifier:
- 1510294
- Grant/Contract Number:
- SC0001299
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Materials
- Additional Journal Information:
- Journal Volume: 11; Journal Issue: 5; Journal ID: ISSN 1996-1944
- Publisher:
- MDPI
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; half-Heusler; NbCoSb; excess Co; thermoelectric performance
Citation Formats
Huang, Lihong, Wang, Junchen, Chen, Xi, He, Ran, Shuai, Jing, Zhang, Jianjun, Zhang, Qinyong, and Ren, Zhifeng. The Effects of Excess Co on the Phase Composition and Thermoelectric Properties of Half-Heusler NbCoSb. United States: N. p., 2018.
Web. doi:10.3390/ma11050773.
Huang, Lihong, Wang, Junchen, Chen, Xi, He, Ran, Shuai, Jing, Zhang, Jianjun, Zhang, Qinyong, & Ren, Zhifeng. The Effects of Excess Co on the Phase Composition and Thermoelectric Properties of Half-Heusler NbCoSb. United States. doi:10.3390/ma11050773.
Huang, Lihong, Wang, Junchen, Chen, Xi, He, Ran, Shuai, Jing, Zhang, Jianjun, Zhang, Qinyong, and Ren, Zhifeng. Fri .
"The Effects of Excess Co on the Phase Composition and Thermoelectric Properties of Half-Heusler NbCoSb". United States. doi:10.3390/ma11050773. https://www.osti.gov/servlets/purl/1510294.
@article{osti_1510294,
title = {The Effects of Excess Co on the Phase Composition and Thermoelectric Properties of Half-Heusler NbCoSb},
author = {Huang, Lihong and Wang, Junchen and Chen, Xi and He, Ran and Shuai, Jing and Zhang, Jianjun and Zhang, Qinyong and Ren, Zhifeng},
abstractNote = {NbCoSb with nominal 19 valence electrons, and is supposed to be metallic, has recently been reported to also exhibit the thermoelectric properties of a heavily doped n-type semiconductor. In this study, we prepared Co-rich NbCo1+xSb samples (x = 0, 0.2, 0.3, 0.4, 0.5), and their phase compositions, microstructures and thermoelectric properties were investigated. The Seebeck coefficient increased a great deal with increasing x, due to decreasing carrier concentration, and the total thermal conductivity reduced mainly because of declining κe. Finally, a peak thermoelectric figure of merit, ZT, was about 0.46 for NbCo1.3Sb at 973 K. This enhancement was mainly attributed to the reduction of electric thermal conductivity and the increase of Seebeck coefficient. The excess Co had effects on the carrier concentration, deformation potential Edef and DOS effective mass m*. Adding an excessive amount of Co leads to a very high Edef, which was detrimental for transport characteristics.},
doi = {10.3390/ma11050773},
journal = {Materials},
number = 5,
volume = 11,
place = {United States},
year = {2018},
month = {5}
}
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