YbCu^sub 2^Si^sub 2^-LaCu^sub 2^Si^sub 2^ Solid Solutions with Enhanced Thermoelectric Power Factors

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 Cryogenic Peltier coolers are ideal for cooling infrared sensors on satellites. To make these thermoelectric devices a realistic option for this application, the efficiency of thermoelectric materials at cryogenic temperatures must be substantially enhanced. Intermediate valence Yb-based compounds have large peaks in the Seebeck coefficient at low temperatures; to optimize these materials this must be understood. We created solid solutions between the intermediate valence compound YbCu^sub 2^Si^sub 2^ and an isostructural compound LaCu^sub 2^Si^sub 2^ to manipulate the temperature at which the Seebeck coefficient peaks and to maximize zT by reduction of lattice thermal conductivity. An enormous power factor of 110 [mu]W/cm K^sup 2^ at 100 K and a maximum zT of 0.14 at 125 K were achieved for one of these solid solutions.