Thermoelectric Properties of the Quasi-Binary MnSi^sub 1.73^-FeSi^sub 2^ System

Issue Title: 2014 International Conference on Thermoelectrics. Guest Editors: Lasse Rosendahl, Donald Morelli, Jihui Yang, Hiroaki Anno, Matt Beekman, Jan D. Koenig, Xinfeng Tang, James R. Salvador, Bertrand Lenoir, Chunlei Wan, Jeff Sharp, Emmanuel Guilmeau, Hsin Wang, Jing-feng Li, Tie-Jun Zhu, David Singh, Ryoji Funahashi, Yuri Grin, and Wenqing Zhang The higher manganese silicides (HMS) are regarded as very attractive p-type thermoelectric materials for direct conversion of heat to electricity. To compete with other thermodynamic engines (e.g. the Stirling and Rankine cycles), however, the thermoelectric figure of merit of such silicides must be improved. HMS follow a complicated solidification reaction on cooling from the melt, which leads to formation of undesired secondary phases. Furthermore, the electronic carrier concentration of HMS is much higher than the optimum for thermoelectric applications and should be compensated by introduction of doping agents. In this research, the electronic donor action associated with substitution of HMS by FeSi^sub 2^ was investigated. The effects of excess Si on phase distribution and thermoelectric properties are also discussed in detail.