Thermoelectric properties of Sb-doped Mg2(Si0.95Ge0.05) synthesized by spark plasma sintering
Thermoelectric properties of Sb-doped Mg2(Si0.95Ge0.05) synthesized by spark plasma sintering
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DOI：
10.1016/j.mseb.2015.01.008
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发表时间：
2015-05-01
影响因子：
3.6
通讯作者：
Nishio, Keishi
中科院分区：
文献类型：
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作者：
Arai, Koya;Sasaki, Asumi;Nishio, Keishi
镁自杀（Mg2Si）作为一种将废热转化为电能的n型热电（TE）材料最近引起了人们的广泛关注。本工作的目的是揭示通过sb掺杂和ge掺杂来提高Mg2Si热电性能的机制。一般采用全熔融法合成Mg2Si。然而，这种合成方法存在一些问题，例如，由于Mg2Si的熔点非常接近Mg的沸点，导致Mg的质量缺陷。在本研究中，我们尝试用火花等离子烧结（SFS）将Mg和Si合金与掺杂物Sb， Ge合成高纯Mg2Si。Ge掺杂样品的ZT值高于未掺杂Ge的相同浓度的sb掺杂样品的ZT值，因为前者的导热系数较低。在756K时，Sb0.23在%掺杂Mg-2（si0.9995 ge0.05）的ZT最大值为0.74。(c) 2015 Elsevier B.V.版权所有
Magnesium suicide (Mg2Si) has recently attracted much interest as an n-type thermoelectric (TE) material for converting waste heat into electric power. The objective of this work was to reveal a mechanism to increase the thermoelectric properties of Mg2Si by Sb-doping and Ge-doping. Generally, Mg2Si is synthesized by all-molten method. However, this synthesis method has some problems, for example, mass defects of Mg for Mg2Si composition caused because the melting point of Mg2Si is very close to the boiling point of Mg. In this study, we tried to synthesize high purity Mg2Si from Mg and Si alloyed with a dopant (Sb, Ge) by spark plasma sintering (SFS). The Ge-doped samples had a higher ZT value than the ZT value of the Sb-doped sample of the same concentration without Ge because the thermal conductivity of the former was lower. The maximum ZT value of Sb0.23 at%-doped Mg-2(Si0.995Ge0.05) was 0.74 at 756K. (c) 2015 Elsevier B.V. All rights reserved.