Abstract

Zintl compounds were recognized as very good thermoelectric candidate due to their characteristics electron-crystal phonon- glass properties. Mg₃Sb₂ is a known Group II–V Zintl semiconductor. This compound is a well-established thermoelectric material and many of recent works focus on this compound due to its intrinsic low thermal conductivity. The band gap of this compound has been shown to be optimum, making it a promising thermoelectric material. This work introduces a new synthetic method and analyzes the thermoelectric properties found using this method. The single phase of Mg₃Sb₂ was synthesized by melting elemental shots at 1173 K for 1 hour in a controlled inert Ar gas atmosphere in a tapped graphite crucible followed by vacuum hot pressing at 873 K for 4 hours. X-ray diffraction and scanning electron microscopy were carried out to investigate existing phases and surface morphology respectively. Thermoelectric properties in terms of Seebeck coefficient, electrical conductivity, and thermal conductivity were evaluated and the results are discussed in comparison to analogous studies. Transport properties were also evaluated and discussed. Single phase magnesium antimonide was found with a nominal formula of Mg_3.8 Sb₂ and showed a comparable ZT value which is ~ 0.24 at 873 K.

Graphic Abstract

中文翻译：

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过量锑对控制熔炼，粉碎，真空热压合成Mg 3 Sb 2的热电和输运性能的影响

摘要

Zintl化合物因其电子晶体声子玻璃特性而被认为是非常好的热电候选物。Mg ₃ Sb ₂是已知的II–V族Zintl半导体。该化合物是一种行之有效的热电材料，由于其固有的低热导率，许多最新的工作集中在该化合物上。该化合物的带隙已显示为最佳，使其成为有前途的热电材料。这项工作介绍了一种新的合成方法，并分析了使用该方法发现的热电性质。Mg ₃ Sb ₂单相通过在抽头石墨坩埚中在受控的惰性Ar气氛中将1173 K的元素喷丸熔化1小时，然后在873 K真空热压4小时，合成了碳纳米管。用X射线衍射和扫描电镜分别研究了存在的相和表面形态。根据塞贝克系数，电导率和热导率评估了热电性能，并与类似研​​究进行了讨论。传输性能也进行了评估和讨论。发现单相锑化镁的名义分子式为Mg _3.8 Sb ₂，在873 K时ZT值约为0.24。

图形摘要