Polycrystalline bulks of Si-content tuned Ge-doped higher manganese silicides (HMSs) were fabricated to elucidate the effects of Si content on the phase formation behavior and thermoelectric properties. The phase formation and electronic transport characteristics of HMSs were significantly dependent on Si content. Improved power factor was obtained at higher Si contents because of an enhanced Seebeck coefficient due to the increase in density of states effective mass, maintaining electrical conductivity. Furthermore, the lattice thermal conductivity was reduced through Si-content tuning, which suppressed the formation of secondary phases. Thus, a maximum ZT of 0.61 at 823 K was obtained in MnSi1.77Ge0.027.
Bibliographical noteFunding Information:
This work was supported by the Korean government (MSIP) (2014R1A2A1A10053869), the Priority Research Centers Program (2009-0093823), through the National Research Foundation of Korea (NRF), and the Industrial Fundamental Technology Development Program (10052977) funded by the Ministry of Trade, Industry and Energy (MOTIE) of Korea.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys