Thermoelectric properties of nanostructured FeSi 2 , Mg 2 Si, and SiGe are compared with their nanocomposites of SiGe–Mg 2 Si and SiGe–FeSi 2 . It was found that the addition of silicide nanoinclusions to SiGe alloy maintained or increased the power factor while further reduced the thermal conductivity compared to the nanostructured single-phase SiGe alloy. This resulted in ZT enhancement of Si 0.88 Ge 0.12 –FeSi 2 by ∼30% over the broad temperature range of 500-950 °C compared to the conventional Si 0.80 Ge 0.20 alloy. The Si 0.88 Ge 0.12 –Mg 2 Si nanocomposite showed constantly increasing ZT versus temperature up to 950 °C (highest measured temperature) reaching ZT ∼ 1.3. These results confirm the concept of silicide nanoparticle-in-SiGe-alloy proposed earlier by Mingo et al. [Nano Lett. 9 , 711–715 (2009)].
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics