Details

Autor(en) / Beteiligte

• Huang, Lihong
• Wang, Junchen
• Chen, Xi
• He, Ran
• Shuai, Jing
• Zhang, Jianjun
• Zhang, Qinyong
• Ren, Zhifeng

Titel

The Effects of Excess Co on the Phase Composition and Thermoelectric Properties of Half-Heusler NbCoSb

Ist Teil von

• Materials, 2018-05, Vol.11 (5), p.773

Ort / Verlag

Switzerland: MDPI AG

Erscheinungsjahr

2018

Link zum Volltext

Quelle

EZB-FREE-00999 freely available EZB journals

Beschreibungen/Notizen

• 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 Sb samples ( = 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 , due to decreasing carrier concentration, and the total thermal conductivity reduced mainly because of declining . Finally, a peak thermoelectric figure of merit, , was about 0.46 for NbCo Sb 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 and DOS effective mass . Adding an excessive amount of Co leads to a very high , which was detrimental for transport characteristics.