Spark Plasma-Induced Combustion Synthesis, Densification, and Characterization of Nanostructured Magnesium Silicide for Mid Temperature Energy Conversion Energy Harvesting Application

Abstract

The excessive consumption of fossil-based fuels and associated environmental pollution from its outlet residuals has raised global warming to critical limits. In this context, thermoelectric (TE) technology is spearheading and promising owing to its direct, simple, and solid-state conversion of waste heat into electrical energy. Synthesis and suitable tailoring of inherent chemistry and introduction of nanoscale grain features in any thermoelectric semiconductors or alloys lead to the superior thermoelectric power factor or figure of merit. Magnesium silicide (Mg2Si) is understood to be a potential semiconducting thermoelectric compound for a medium functional temperature range (600°C). It is due to appreciating traits such as lower density, better thermo-physical properties, cost-effective and eco-friendly constituent elements. The present chapter details the simple and robust attempt to fabricate nanocrystalline Mg2Si bulk compound from mechanically milled Mg-Si powders by coupling self-propagating high-temperature synthesis (SHS) and spark plasma sintering (SPS). The synthesis mechanism is systematically presented with the characterization (X-ray diffraction, electron microscopy analysis, and electron backscattered diffraction) and thermoelectric properties.