Fabrication and thermoelectric property of nanostructured Si/Cr<inf>0.8</inf>Mn<inf>0.2</inf>Si<inf>2</inf> eutectic alloy by melt-spinning

In the present study, we synthesized nanometer-sized composite of Si and (Cr,Mn)Si2 with the eutectic composition. The appropriate Cr/Mnratio and correct eutectic composition were examined. The n-Type nanostructured P-doped Si-Cr0.80Mn0.20Si2 eutectic alloy was successfully fabricated by melt-spinning. The ribbon-like samples were obtained with lamellar spacing range of 20-40 nm. The ribbons were then pulverized and sintered by spark plasma sintering with the size of the morphology change to about 100-200 nm. The thermal conductivity of sintered sample was reduced by 20%-30% at room temperature, which results in increase of the dimensionless figure-of-merit value by 50%. The self-organizing structure refinement process, based on liquid quenching at the eutectic reaction, is considered to be an effective method to enhance the thermoelectric performance.