Process optimisation enhancing thermoelectric and mechanical performance in reactive in-situ spark plasma sintered Mg2(Si,Sn)

Enhancement of Power Factor and Mechanical Properties in Low Cost Mg2Si1–xSnx Employing a Composite Approach

“…Furthermore, the XRD analysis reveals the crystallite size in the ranges ∼39, 41, 36, and 53 nm for Mg 2 (Si 0.9 Sn 0.1 ) 0.95 ­Sb 0.05 , Mg 2 (Si 0.9 Sn 0.1 ) 0.95 ­Sb 0.05 -5 wt % MnSi, Mg 2 (Si 0.9 Sn 0.1 ) 0.95 ­Bi 0.05 , and Mg 2 (Si 0.9 Sn 0.1 ) 0.95 ­Bi 0.05 -5 wt % MnSi, respectively. Also, XRD analysis confirms the inevitable MgO presence in the sintered material irrespective of doping and reinforcement addition, and the occurrence of MgO during Mg 2 Si 1– x Sn x synthesis is reported elsewhere. , …”

“…On the other hand, magnesium–silicon based thermoelectric materials possess abundant and low cost constituent elements, which advances shifting the paradigm of thermoelectric device applications from niche to widespread commercial applications. − Furthermore, low specific weight Mg 2 Si 1– x Sn x materials have received more attention in recent decades and are an economical way to realize thermoelectric generators in waste heat recovery applications, particularly in automotive sectors. A decade of intense research on the chemically stoichiometric Mg 2 Si 1– x Sn x materials has been extensively explored, including elemental doping, − alloying, ,− and adopting a complex materials synthesis process. ,,,− Several strategies have been reported on Mg 2 Si 1– x Sn x material to enhance its thermoelectric properties, such as nanostructuring, nanoparticle inclusion, and single/double element doping. ,− However, although most of the published studies have reported the improved properties, the stable Mg 2 Si 1– x Sn x material is problematic due to the tendency for magnesium oxidation. ,, …”

“…Decomposition and controlled phase separation of Mg 2 Si 1– x Sn x material has been reported by Andersen et al; however, the thermoelectric and mechanical properties are not well-correlated to confirm its feasibility. Choudhary et al have reported higher thermoelectric properties and hardness values of sintered Mg 2 Si 0.9 Sn 0.1 material employing the SPS process parameter optimization. Zhou et al have explored the strategy of improving thermoelectric properties using a layered structure via microstructural engineering.…”

“…However, the research work emphasis on mechanical stability is minimal. High brittleness associated with high crack propagation in Mg 2 Si 1– x Sn x material drives low mechanical reliability, impeding their practical applications in thermoelectric devices. , For thermoelectric generator applications, the material should possess superior thermoelectric properties, high thermal stability, and mechanical robustness. Recently, the temperature-dependent mechanical properties of Mg 2 Si 1– x Sn x materials have been reported, varying the Si/Sn composition by G. Castillo-Hernandez et al Unfortunately, the mechanical properties enhancement in Mg 2 Si 1– x Sn x employing various techniques such as nanostructuring and nanoinclusions leads to inferior thermoelectric properties.…”

Nanostructure Approach Enhancing the Thermoelectric Performance of a p-Type HMS-CrSi2 Composite Synthesized by the MS–SPS Technique

“…Abundant and nontoxic thermoelectric elements are prerequisites for developing thermoelectric devices for green energy applications. , However, the low thermoelectric performance and n and p-type compatibility issues limit their commercial power generation applications. Among the family of silicides, n-type Mg 2 Si and p-type MnSi 1.73 are evolving as the best combination material for realizing cost-effective thermoelectric devices. − However, the figure-of-merit ( zT ) of a p-type MnSi 1.73 material is far below unity, restricting thermoelectric conversion efficiency. At present, doping and substitution are used to improve the thermoelectric performance of narrow-region semiconducting higher manganese silicides (HMSs).…”