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A2: Medium temperature materials

Thermoelectric investigation of pseudo binary system PbTe-CoSe2*

 V. Ponnambalam and D.T. Morelli
Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI  48824-1226

In the quest of finding new high efficient thermoelectric materials, we have recently undertaken the pseudo binary system PbTe-CoSe2 for thermoelectric investigations. According to the phase diagram, the solid solubility limit of CoSe2 can be up to 12 % in PbTe. In addition, a tetragonal phase PbCoSe2Te forms with a large unit cell (a= 9.85 Å and b= 10.41 Å). Since solid solutions and larger unit cells tend to give lower thermal conductivity, these compositions can potentially exhibit lower thermal conductivity than that of PbTe. Several (PbTe)1-x(CoSe2)x type compositions and PbCoSe2Te have been synthesized. Thermoelectric properties including resistivity, Seebeck and Hall coefficients, and thermal conductivity will be measured over a wide temperature range on dense samples. These results and the figures of merit will be presented. The thermoelectric potential of these solid solutions will be discussed.

 

* This work was supported as part of the Center for Revolutionary Materials for Solid State Energy Conversion, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001054.