Synthesis, crystal structure, and thermoelectric properties of the YDAl_3-SCAl_3 solid solution

摘要

The Yb_(1-x)Sc_xAl3 alloy solid solution has been successfully synthesized for 0 < x < 1 by a combination of arc melting, pulverization, and consolidation by pulsed electric current sintering, The thermoelectric properties of the alloys have been investigated over the temperature range .80-300 K Our results on pure YbAb confirm previous studies demonstrating the combination of low electrical resistivity (~ 100 (iO cm) and large Seebeck coefficient (~ 85 μV K~(-1)) at 300 K. With increasing values of x the alloys become even more metallic, but the Seebeck coefficient decreases more gradually than the resistivity, resulting in enhanced thermoelectric power factor for 0 < x < 1. An increase in electronic thermal conductivity is partially offset by a strong suppression in lattice thermal conductivity that arises due to alloy scattering. As a result, the thermoelectric figure of merit of alloys with x = 0.25 is increased by 30% relative to YbAl_3 at 250 K.