Thermoelectric Properties of xPbTe/Yb0.2Co4Sb12 Hot-Pressed Samples
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The xPbTe/Yb0.2Co4Sb12 compounds were prepared by the ball-milling and hot-pressed process. Electrical conductivity of the composite samples are reduced with a increase in PbTe content; and, their temperature dependence coefficients show the positive values. The maximum electrical conductivity of composite materials is ~80000 Sm−1 at 800 K. The Seebeck coefficient (absolute value) of the composite material is obviously improved with an increase in the dispersed phase (PbTe) content; the Seebeck coefficient (absolute value) of the 10PbTe sample is ~260 μVK−1 at 700 K, which increases by 13.6% relative to that of the Yb0.2Co4Sb12 sample. The thermal conductivity of the composite samples is improved due to introduction of PbTe, and the thermal conductivity of the 10PbTe sample is ~3 Wm−1 K−1 at 550 K. The maximum value of ZT is 0.78 at 700 K for the 2.5PbTe sample.
KeywordsThermoelectric materials Composite Thermoelectric properties Thermal conductivity
The authors acknowledge support by Natural Science Foundation of China under Grant No. 50801054.