Thermoelectric Figure of Merit of Some Compositions in the System (GeTe)_1−x[(Ag₂Te)_1−y(Sb₂Te₃)_y]_x

Basic thermoelectric p-type materials for the medium temperature range (600 to 900 K) are GeTe-based materials. Hot-pressed samples of (GeTe)_1−x[(Ag₂Te)_1-y(Sb₂Te₃)_y]_x solid solutions with y = 0.6, y = 0.75 are prepared. Their thermoelectric properties (thermoelectric power S, electric conductivity σ and thermal conductivity K) in the temperature range 300 to 750 K are measured. The thermoelectric figure of merit Z = S²σ/K for some compositions in calculated. The best p-type new material is the composition (GeTe)₀.₈[(Ag₂Te)_0.4(Sb₂Te₃)_0.6]_0.2 with Z_max = 2.4 × 10⁻³ K⁻¹ at about 700 K.