Exploring the thermoelectric behavior of spark plasma sintered Fe7-xCoxS8 compounds
Exploring the thermoelectric behavior of spark plasma sintered Fe7-xCoxS8 compounds
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DOI：
10.1016/j.jallcom.2019.152999
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发表时间：
2020-04
影响因子：
6.2
通讯作者：
J. Simon;G. Guélou;B. Srinivasan;D. Berthebaud;T. Mori;A. Maignan
中科院分区：
文献类型：
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作者：
J. Simon;G. Guélou;B. Srinivasan;D. Berthebaud;T. Mori;A. Maignan
硫化物基材料正在成为目前最先进的热电材料的可行替代品，这些材料通常由有毒，昂贵和稀缺的元素组成。在这里，一个这样的廉价和环境友好的硫化物为基础的系统，即Fe 7-xCoxS 8磁黄铁矿型化合物，通过固相反应合成和致密化的火花等离子烧结的结构和热电性能进行了系统的研究。我们报道了Co取代Fe后磁黄铁矿的结构由单斜4C超结构转变为三角3C超结构;通过降低磁有序温度和磁化强度改变了磁行为;改变了主要载流子的类型（iv）减少声子对热导率的贡献;和（v）当与原始磁黄铁矿的热电品质因数相比时，放大了热电品质因数。
Sulfide-based materials are emerging as viable alternatives for the current state-of-the-art thermoelectric materials, which usually are composed of toxic, expensive and scarce elements. Here, a systematic study of one such inexpensive and environmentally friendly sulfide-based system,i.e. Fe7-xCoxS8pyrrhotite-type compounds that were synthesized by solid-state reaction and densified by Spark Plasma Sintering are investigated for their structural and thermoelectric properties. We report that substitution of Co for Fe in pyrrhotites: (i) induces structural transition from monoclinic 4C superstructure to trigonal 3C superstructure; (ii) modifies the magnetic behavior by decreasing the magnetic ordering temperature and magnetization; (iii) alters the type of dominant charge carriers (fromp-ton-type) and enhances their electrical transport properties; (iv) mitigates the phonon contribution to the thermal conductivity; and (v) amplifies the thermoelectric figure of merit when compared with that of pristine pyrrhotites.