Broader Impacts Susan M. Kauzlarich, University of California-Davis, DMR 1100313

1. Synthesis of Zintl Phases for Themoelectric ApplicationsSusan M. Kauzlarich, University of California-Davis, DMR 1100313 Yb14MnSb11 was recently discovered to be one of the highest efficiency p-type thermoelectric materials for high temperature applications. However, with further research this material could be improved even further. The efficiencies of thermoelectric materials are compared using the unitless figure of merit known as zT. zT depends interrelated properties of the material: electrical resistivity, thermal conductivity, and the Seebeck coefficient. Recent work has shown that partial substitution of Ce for Yb in Yb14MnSb11 causes an undesired increase in resistivity, but also leads to a favorable increase in Seebeck coefficient. The overall effect is an increase in the zT of the material. The thermoelectric figure of merit (zT) depends on electrical resistivity ρ, thermal conductivity κ, and the Seebeck coefficient α. Yb13.68Ce0.32MnSb11 (red) shows an enhanced thermoelectric figure of merit (zT) over Yb14MnSb11 (black).

2. Broader Impacts Susan M. Kauzlarich, University of California-Davis, DMR 1100313 Substantial contributions towards studying the effects of different substitutions in Yb14MnSb11 have been made by UC Davis undergraduate Francisco Ortega and recent high school graduate Jennifer Karolewski, who will be attending Caltech in the fall. Jennifer’s research has been focused on substitutions for Mn, while Francisco has been primarily working on substitutions of Sc for Yb. Both students have also been assisting with the development of a new synthesis for Yb14MnSb11 compounds. Jennifer Karolewski sorts crystals in a glove box. Francisco Ortega presents his research on Sc substituted Yb14MnSb11.