Abstract Here, we report on an economical, viable, one-step method for fabrication of Higher Manganese Silicide MnSi1.75 (HMS). Fabrication of the HMS was followed by spark plasma sintering (SPS) at different temperatures (850, 900, 950 and 1000 °C), after which the thermoelectric and mechanical properties were investigated. It was found that the electrical conductivity significantly increased with increasing SPS temperature. This was attributed to the simultaneous increase of carrier concentration and mobility, while a reduction in the Seebeck coefficient was attributed to the formation of secondary phase in the HMS samples. A low thermal conductivity of 1.86 W/mK at 723 K was obtained for the sample sintered at 850 °C, which was attributed to increased scattering of heat-carrying phonons due to pores or voids, and grain boundaries. In addition, a maximum ZT of 0.27 was obtained at 723 K for the HMS-1000 sample, which is comparable with other previously reported data for undoped HMS material. Nevertheless, the HMS-1000 sample exhibited compressive strength of 1208 MPa and fracture toughness of 1.99 MPa m1/2, which is significantly higher than other state-of-the-art thermoelectric materials. The proposed fabrication method could be adopted for mass market applications requiring superior mechanical and thermoelectric properties.

中文翻译：

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水雾化放电等离子烧结法制备环保型高硅化锰的机械和热电性能

摘要 在这里，我们报告了一种经济、可行的一步法制造高硅化锰 MnSi1.75 (HMS)。制造 HMS 之后，在不同温度（850、900、950 和 1000 °C）下进行放电等离子烧结（SPS），然后研究热电和机械性能。发现电导率随着SPS温度的升高而显着增加。这归因于载流子浓度和迁移率的同时增加，而塞贝克系数的降低归因于 HMS 样品中第二相的形成。在 850 °C 下烧结的样品在 723 K 下获得了 1.86 W/mK 的低热导率，这归因于由于孔隙或空隙和晶界导致的载热声子散射增加。此外，HMS-1000 样品在 723 K 下获得的最大 ZT 为 0.27，这与之前报道的未掺杂 HMS 材料的其他数据相当。尽管如此，HMS-1000 样品的抗压强度为 1208 MPa，断裂韧性为 1.99 MPa m1/2，明显高于其他最先进的热电材料。所提出的制造方法可用于需要优异机械和热电性能的大众市场应用。