Microstructure and thermoelectric properties of the medium-entropy BiSbTe₁.₅Se₁.₅ and PbSnTeSe compounds prepared by reactive spark plasma sintering

Reactive spark plasma sintering (RSPS) is used to obtain single-phase samples of medium-entropy BiSbTe₁.₅Se₁.₅ compounds (low-temperature thermoelectric electronic type of conductivity) and PbSnTeSe (medium temperature hole-type thermoelectric conductor) from a mixture of powders of the corresponding elemental metals. The obtained samples are polycrystalline with lamellar grains with the average size of ~3.3 μm in BiSbTe₁.₅Se₁.₅ and with irregularly shaped grains with the average size of ~18.9 μm in PbSnTeS