Enhancement of thermoelectric performance in TiNiSbxSn1-x half-Heusler alloys

• Published in: Journal of solid state chemistry 2023-07, Vol.323, p.124060, Article 124060
• Main Authors: Gao, Feng, Lei, Ying, Li, Yu, Qiu, Jin, Yong, Chao, Wang, Nan, Song, Guangyuan, Hu, Huaichuan
• Format: Article
• Language: English
• Subjects: Annealing; Microwave synthesis; Power factor; Sb doping; TiNiSn-based half-Heusler
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2023.124060

In this paper, TiNiSn1-xSbx thermoelectric bulks were fabricated by microwave synthesis combined with spark plasma sintering and annealing process. The high density of the samples were confirmed by the physical phase analysis and microstructure characterization of the samples. Through the analysis of the thermoelectric properties of the samples, it was determined that the antimony doping and the annealing process resulted in a significant improvement in the electrical properties of the TiNiSn-based materials, and allowed the samples to maintain relatively low lattice thermal conductivity. At the same time, the lattice thermal conductivity of all samples is less than 1.7 W m−1K−1 at high temperature. TiNiSn0.965Sb0.035 obtained a maximum power factor of 3125.9 μW m−1K−2 at 873 K and a total thermal conductivity of 4.2–4.7 W m−1K−1, with the maximum ZT value of 0.57, which is ∼86% higher than that of the undoped sample. [Display omitted] •TiNiSbxSn1-x was synthesized by microwave heating in 6 min.•The maximum power factor of 3125.9 μW m−1K−2 was achieved in TiNiSn0.965Sb0.035.•The lattice thermal conductivity of all samples is less than 1.7 W m−1K−1.•The highest ZT of 0.57 was achieved at 873 K.