High-performance half-Heusler thermoelectric materials Hf1−x ZrxNiSn1−ySby prepared by levitation melting and spark plasma sintering
High-performance half-Heusler thermoelectric materials Hf1−x ZrxNiSn1−ySby prepared by levitation melting and spark plasma sintering
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DOI：
10.1016/j.actamat.2009.02.026
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发表时间：
2009-05
期刊：
影响因子：
9.4
通讯作者：
Cui Yu;T. Zhu;Rui-Zhi Shi;Yun Zhang;Xinbing Zhao;Jian He
中科院分区：
文献类型：
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作者：
Cui Yu;T. Zhu;Rui-Zhi Shi;Yun Zhang;Xinbing Zhao;Jian He
采用悬浮熔融、火花等离子烧结或热压法制备了半赫斯勒热电材料Hf1−xZrxNiSn1−ySby（x= 0,0.25, 0.4, 0.5; y=0.02, 0.04, 0.06）。x射线衍射分析和扫描电镜观察表明，通过悬浮熔炼获得了无组分分离的单相半heusler化合物。少量Sb的掺杂可以改善电功率因数，但由于载流子导热系数的增加而增加了导热系数。Zr对Hf的等电子取代大大降低了晶格导热系数。在1000K条件下，悬浮熔化和火花等离子体烧结的Hf0.6Zr0.4NiSn0.98Sb0.02的ZT达到了最先进的1.0，这是半heusler热电合金ZT达到的最高值之一。
Half-Heusler thermoelectric materials Hf1−xZrxNiSn1−ySby(x=0, 0.25, 0.4, 0.5; y=0.02, 0.04, 0.06) have been prepared by levitation melting followed by spark plasma sintering or hot pressing. X-ray diffraction analysis and scanning electron microscopy observation show that single-phased half-Heusler compounds without compositional segregations have been obtained by levitation melting in a time-efficient manner. A small amount of Sb doping can improve the electrical power factor but undesirably increases the thermal conductivity due to the increased carrier thermal conductivity. The isoelectronic substitution of Zr for Hf substantially decreased the lattice thermal conductivity. A state-of-the-art ZT value of 1.0 has been attained at 1000K for the levitation-melted and spark-plasma-sintered Hf0.6Zr0.4NiSn0.98Sb0.02, which is one of the highest achieved ZT values for half-Heusler thermoelectric alloys.