Hot deformation induced defects and performance enhancement in FeSb2 thermoelectric materials
Hot deformation induced defects and performance enhancement in FeSb2 thermoelectric materials
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DOI：
10.1063/1.4831668
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发表时间：
2013-11
影响因子：
3.2
通讯作者：
Yongzhen Wang;C. Fu;T. Zhu;Lipeng Hu;G. Jiang;Guanghui Zhao;D. Huo;Xinbing Zhao
中科院分区：
文献类型：
--
作者：
Yongzhen Wang;C. Fu;T. Zhu;Lipeng Hu;G. Jiang;Guanghui Zhao;D. Huo;Xinbing Zhao
研究了热变形缺陷和织构对FeSb2块体晶体热电性能的影响。在3 ~ 300 K范围内测量了样品沿平行和垂直方向的输运特性。结果表明，变形试样的导热系数明显降低。2次变形后，试样沿垂直受压方向的导热系数降至4 W/mK，仅为变形前的1 / 3。透射电镜观察发现，变形试样中存在高密度的晶格缺陷。利用Debye-Callaway近似分析了晶格的热导率，结果表明变形引起的晶格缺陷在增强声子散射中起重要作用。变形试样的电阻率和塞贝克系数均表现出较弱的各向异性。变形后块状FeSb2的优异值ZT由0.010显著提高到0.021。
The effect of hot deformation induced defects and texture on thermoelectric properties of FeSb2 bulk crystals has been investigated. The transport properties of the samples along both parallel and perpendicular direction of pressing were measured from 3 K to 300 K. The results showed that thermal conductivity of the deformed samples was significantly reduced. After twice deformation, the thermal conductivity of the sample along the perpendicular direction of pressing was decreased to 4 W/mK, which was only one third of that before deformation. Transmission electron microscopy observation revealed the presence of high density of lattice defects in the deformed samples. The lattice thermal conductivity was analyzed using the Debye-Callaway approximation, and the results showed that the deformation induced lattice imperfections play an important role in enhancing phonon scattering. In addition, both the electrical resistivity and Seebeck coefficient exhibited a weak anisotropy in the deformed samples. The figure of merit ZT of the bulk FeSb2 was significantly improved from 0.010 to 0.021 after deformation.