Chen Jun-Liang, Yang Hengquan, Liu Chengyan, Liang Jisheng, Miao Lei, Zhang Zhongwei, Liu Pengfei, Yoshida Kenta, Chen Chen, Zhang Qian, Zhou Qi, Liao Yuntiao, Wang Ping, Li Zhixia, Peng Biaolin
School of Chemistry and Chemical Engineering & School of Physical Science and Technology, Guangxi University, Nanning 530004, China.
School of Physics and Electronic & Electrical Engineering, and Jiangsu Key Laboratory of Modern Measurement Technology and Intelligent Systems, Huaiyin Normal University, Huai'an 223300, China.
ACS Appl Mater Interfaces. 2021 Oct 20;13(41):48801-48809. doi: 10.1021/acsami.1c14723. Epub 2021 Oct 7.
Half-Heusler alloys, which possess the advantages of high thermal stability, a large power factor, and good mechanical property, have been attracting increasing interest in mid-temperature thermoelectric applications. In this work, extra Zr-doped TiZrNiSn samples were successfully prepared by a modified solid-state reaction followed by spark plasma sintering. It demonstrates that extra Zr doping could not only improve the power factor on account of an increase in the Seebeck coefficient but also suppress the lattice thermal conductivity originated from the strengthened phonon scattering by the superlattice nanodomains and the secondary nanoparticles. As a consequence, an increased power factor of 3.29 mW m K and a decreased lattice thermal conductivity of 1.74 W m K are achieved in TiZrNiSn, leading to a peak ZT as high as 0.88 at 773 K and an average ZT value up to 0.62 in the temperature range of 373-773 K. This work gives guidance for optimizing the thermoelectric performance of TiNiSn-based alloys by modulating the microstructures on the secondary nanophases and superlattice nanodomains.
半赫斯勒合金具有高热稳定性、大功率因子和良好机械性能等优点，在中温热电应用中越来越受到关注。在本工作中，通过改进的固态反应结合放电等离子烧结成功制备了额外Zr掺杂的TiZrNiSn样品。结果表明，额外Zr掺杂不仅由于塞贝克系数的增加而提高了功率因子，还通过超晶格纳米畴和二次纳米颗粒增强了声子散射，从而抑制了晶格热导率。结果，TiZrNiSn的功率因子提高到3.29 mW m K，晶格热导率降低到1.74 W m K，在773 K时峰值ZT高达0.88，在373 - 773 K温度范围内平均ZT值高达0.62。本工作为通过调控二次纳米相和超晶格纳米畴的微观结构优化TiNiSn基合金的热电性能提供了指导。
