The Effects of Excess Co on the Phase Composition and Thermoelectric Properties of Half-Heusler NbCoSb
Year: 2018
Type: article
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 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.
Source: Materials
DOI: 10.3390/ma11050773
Authors: Lihong Huang, Junchen Wang, Xi Chen, Ran He, Jing Shuai, Jianjun Zhang, Qinyong Zhang, Zhifeng Ren
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
Awards: 势垒过滤优化典型Half Heusler材料热电性能的研究, 双能垒对p型Mg2X材料输运过程和热电性能影响的研究, G29355420, NEW: SOLID-STATE SOLAR-THERMAL ENERGY CONVERSION CENTER (S3TEC CENTER) -- EFRC; PI - GANG CHEN, NEW: SOLID-STATE SOLAR-THERMAL ENERGY CONVERSION CENTER (S3TEC CENTER) -- EFRC; PI - GANG CHEN, 共振散射优化p型IV-VI材料热电性能的研究, G8559846019
OpenAlex ID: W2800187898