Improved Power Factor and Mechanical Properties of Composites of Yb 14 MgSb 11 with Iron
Improved Power Factor and Mechanical Properties of Composites of Yb 14 MgSb 11 with Iron
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Yb 14 MgSb 11 与铁复合材料改善功率因数和机械性能
DOI：
10.1021/acsaem.9b02168
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发表时间：
2020
影响因子：
6.4
通讯作者：
Kauzlarich, Susan M.
中科院分区：
文献类型：
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作者：
Perez, Christopher J.;Qi, Xiao;Chen, Zhijie;Bux, Sabah K.;Chanakain, Sevan;Li, Billy;Liu, Kai;Dhall, Rohan;Bustillo, Karen C.;Kauzlarich, Susan M.
复合相已被证明可以提高材料的热电效率和机械性能。在这里，我们展示了一个改进的热电优值，功率因数，和机械性能的高温p型Zintl相Yb 14 MgSb 11。通过快速、可扩展的机械球磨和放电等离子烧结工艺制备了含有0、1、2、3、4、6和8体积% 6-10 μm还原铁粉的复合材料。粉末X射线衍射，扫描电子显微镜，透射电子显微镜表明，铁没有纳入Yb 14 MgSb 11结构。一级反转曲线和扫描电镜图像表明，随着Fe含量的增加，Fe夹杂物变得更大，更紧密。热重分析和差示扫描量热分析表明，复合材料在1273 K以下是稳定的.的弹性常数的8体积%的铁复合材料的共振超声光谱测量，并显示，Yb 14 MgSb 11变得更硬，增加Fe体积%和SEM压痕后显示裂纹止裂发生在Fe界面。在300 K - 1273 K范围内测量了致密球团的热电性能。热电功率因数（PF =S2/ρ）随着Fe含量的增加而增加，其中8vol% Fe导致PF比原始Yb 14 MgSb 11高40%。PF的增加归因于电阻率的系统性降低。在3体积% Fe处观察到峰值热电优值[zT=（S2 T）/（κρ）]，与Yb 14 MgSb 11相比，zT提高了11%。Yb 14 MgSb 11/Fe复合材料与Ce0.9Fe3.5Co0.5Sb12相兼容，用于热电偶分割。
Composite phases have been shown to improve both the thermoelectric efficiency and mechanical properties of materials. Here, we demonstrate an improved thermoelectric figure of merit, power factor, and mechanical properties for the high-temperaturep-type Zintl phase Yb14MgSb11. Composites with 0, 1, 2, 3, 4, 6, and 8 vol % 6–10 μm reduced Fe powder were prepared via a fast, scalable, mechanical milling and spark plasma sintering procedure. Powder X-ray diffraction, scanning electron microscopy, and transmission electron microscopy show that Fe is not incorporated into the Yb14MgSb11structure. First-order reversal curves and scanning electron microscopy images show that the Fe inclusions are larger and closer together with increasing Fe content. Thermogravimetric and differential scanning calorimetry show that the composites are stable up to 1273 K. The elastic constants of the 8 vol % Fe composite were measured by resonant ultrasound spectroscopy and show that Yb14MgSb11becomes stiffer with increasing Fe volume % and SEM after indentations show crack arresting occurs at the Fe interface. Thermoelectric properties on dense pellets are measured from 300 K – 1273 K. The thermoelectric power factor (PF =S2/ρ) increases with increasing Fe content, with the 8 vol % Fe resulting in 40% higher PF than pristine Yb14MgSb11. The increase in PF is attributed to a systematic reduction in electrical resistivity. Peak thermoelectric figure of merit [zT= (S2T)/(κρ)] is observed at 3 vol % Fe, an 11% improvement in zT compared to Yb14MgSb11. Yb14MgSb11composites with Fe are compatible with Ce0.9Fe3.5Co0.5Sb12for thermoelectric generator couple segmentation.