Enhancement of Thermoelectric Efficiency of MnSi1.75 with the Addition of Externally Processed Nanostructured MnSi

Higher manganese silicide is one of the promising thermoelectric materials for waste heat recovery at medium temperature (500-700°C). Improvement on thermoelectric performance of bulk thermoelectric higher manganese silicide MnSi_1.75 is introduced by externally mixing 1 at% nanostructured MnSi to MnSi_1.75. This method can reduce the thermal conductivity above 400 °C more than reducing the power factor of the higher manganese silicide. This would enhance the figure-of-merit ZT of MnSi_1.75 to ZT≅0.5 without any doping at 570°C. In comparison, the figure-of-merit of conventional MnSi_1.75 is ZT≅0.3. This method can be easily applied to industrial manufacturing of this material to enhance its efficiency.