In-situ reactive synthesis of dense nanostructured β-FeSi2 by Spark Plasma Sintering

beta-FeSi2 is a promising material for thermoelectric application, especially if it can be nanostructured to decrease the lattice contribution to the thermal conductivity. It can be even more interesting if the entire chain of processes implemented to obtain it is not too time and energy consuming. In this paper we report a simple route to synthesize nano-beta-FeSi2 by combining mechanical milling and reactive spark plasma sintering of Fe-Si alloys. A map of the pressure-temperature conditions using a spark plasma sintering setup was performed and shows that it is possible to obtain nano-beta-FeSi2 pellets with a density above 90% using dwell times as short as 5 min. The impact, of both, the density and nanostructuring on the hardness of the beta FeSi2 pellets obtained by this process are presented as well as the impact of the thermoelectric properties of the materials. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this paper, a simple route to synthesize nano-beta-FeSi2 material is reported. The impact of spark plasma sintering parameters on the material properties is studied. Experimental results show that high-density nano-beta-FeSi2 pellets can be obtained using this method in a short time.