Low-Temperature Transport Coefficients of Nanostructured Bi^sub 0.4^Sb^sub 1.6^Te^sub 3^-Based Thermoelectric Materials Obtained by Spark Plasma Sintering

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 temperature dependences of the electrical conductivity and Hall coefficient of spark-plasma-sintered nanostructured thermoelectric materials based on p-Bi^sub 0.4^Sb^sub 1.6^Te^sub 3^ solid solution were measured in the range of 15 K to 300 K for a set of samples sintered at different temperatures from 300°C to 550°C. These data allow estimation of the mean free path of holes. Analysis of the transport coefficients together with information on the size and internal structure of the nanocrystalline grains indicates the important role of point defects in hole scattering, being more intensive for samples obtained at lower sintering temperature. The possible nature of the defects is discussed based on the transport and structural data.