Thermoelectric properties of medium-entropy PbSbTeSe alloy prepared by reactive spark plasma sintering

Reactive spark plasma sintering combining the synthesis and densification stages has been at the first time applied to prepare medium-entropy grained PbSbTeSe alloy. This alloy is prospect medium-temperature p-type thermoelectric. Self-propagating high-temperature synthesis in initial mixture of elemental Pb, Sb, Te and Se powders, resulting in synthesis of single-phased PbSbTeSe, was stage of synthesis. Lattice thermal conductivity of the alloy is very low (-0.7 at 755 K). Owing to this low lattice thermal conductivity, thermoelectric performance of PbSbTeSe alloy is promising . Highest thermoelectric figure-of-merit equal to 0.43 is observed at 720 K. Anomalies of thermoelectric properties were found at 490 K. These anomalies can be related to specific features of energy bands, consisting of two valence bands, which are close in energy.