High-Temperature Thermoelectric Properties of Ge-Substituted p-Type Nd-Filled Skutterudites
High-Temperature Thermoelectric Properties of Ge-Substituted p-Type Nd-Filled Skutterudites
复制标题
锗取代 p 型钕填充方钴矿的高温热电性能
DOI：
10.1007/s11664-016-5079-z
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发表时间：
2017
影响因子：
2.1
通讯作者：
Zhou Xiaoyuan
中科院分区：
文献类型：
--
作者：
Shaheen Nusrat;Shen Xingchen;Javed Muhammad Sufyan;Zhan Heng;Guo Lijie;Alsharafi Rashed;Huang Tianyu;Lu Xu;Wang Guoyu;Zhou Xiaoyuan
为了阐明Ge取代对Nd填充p型方钴矿电输运性能的影响，通过固态反应方法和放电等离子体烧结工艺合成了一系列组成x= 0、0.1、0.2、0.3和0.4的Nd0.9Fe2Co2Sb12−xGex化合物。通过 X 射线衍射分析对制备的样品的晶体结构进行了表征，表明成功形成了方钴矿作为主要纯相。对于固定的 Nd 填料含量，研究了电和热传输特性与 Ge 掺杂含量的函数关系。所有样本均具有正塞贝克系数，表明有效的 p 型行为。轻掺杂样品（x= 0.1 和 0.2）在整个温度范围内表现出更高的品质因数，其中 x= 0.2 样品在 674 K 时显示出最高的 ZT 值 0.56，比无 Ge 样品高 40%。 ZT 的增强可归因于优化的载流子浓度和降低的热导率。然而，Ge含量的进一步增加会导致基体中出现第二相，从而降低总体ZT。通过Ge掺杂，ZT的大幅提高表明这些化合物在热电器件的asp型段方面具有巨大的应用潜力。
To clarify the influence of Ge substitution on the electrical transport properties of Nd-filledp-type skutterudites, a series of Nd0.9Fe2Co2Sb12−xGexcompounds with compositionsx= 0, 0.1, 0.2, 0.3, and 0.4 were synthesized by a solid-state reaction method followed by a spark plasma sintering process. The crystal structure of the prepared samples was characterized by x-ray diffraction analysis, revealing successful formation of skutterudites as main pure phase. The electrical and thermal transport properties were investigated as a function of Ge doping content for fixed Nd filler content. All samples possessed positive Seebeck coefficient, indicating effectivep-type behavior. The lightly doped samples (x= 0.1 and 0.2) showed higher figure␣of merit over the entire temperature range, with thex= 0.2 sample showing the highestZTvalue of 0.56 at 674 K, 40% higher than that of the Ge-free sample. The enhancement inZTcan be ascribed to the optimized carrier concentration and reduced thermal conductivity. However, further increase of the Ge content resulted in second phase in the matrix, lowering the overallZT. The large enhancement ofZTthrough Ge doping indicates that these compounds may have great potential for application asp-type segments of thermoelectric devices.