Solid solution Pb1-xEuxTe: constitution and thermoelectric behavior

Polycrystalline samples of the solid solution Pb1-xEuxTe were prepared by the spark-plasma technique. In contrast to the literature data, the homogeneity range of the solid solution amounts only to 0 <= x <= 0.02 under the selected preparation conditions. The implementation of Eu into the PbTe lattice was monitored by refinement of the lattice parameters. The thermoelectric properties of the prepared materials were investigated above room temperature. In samples with compositions x <= 0.04, the solid solution Pb1-xEuxTe reveals a metal-semiconductor transition around 500 K going in parallel to the p-n transition in the conductivity. No significant influence of the europium substitution on the thermoelectric figure-ofmerit was observed in stoichiometric bulk materials.