Effect of Sn Content on the Electrical Properties and Thermal Conductivity of Pb<SUB>1−<I>x</I></SUB>Sn<I><SUB>x</SUB></I>Te

Abstract

P-type Pb 1-x Sn x Te single crystals were prepared by the Bridgman method with different Sn content (x). Electrical conductivity (σ ), Hall coefficient (R H ) and thermal conductivity (κ) were measured in the temperature range from 300 to 700 K. The hole concentration (p) at 77 K changed in the range from 2.2 × 10 24 to 4.9 × 10 26 m -3 for a whole composition range, 0.0 ≤ x ≤ 1.0. The σ increased monotonously with increasing x, while the κ value exhibited a minimum at x = 0.25. The lattice thermal conductivity (κ lattice ) also changed with x showing a minimum at x = 0.25 ∼ 0.50. The carrier thermal conductivity (κ carrier ) was found to increase monotonously with increasing x. The ratio (σ/κ) of electrical conductivity to thermal conductivity was found to have a maximum at x = 0.50. These results indicate that the electrical and thermal properties are sensitively influenced by phonon scattering by the disordered atomic arrangements in the solid solution. The possible enhancement of thermoelectric performance was suggested by forming the Pb 1-x Sn x Te solid solutions.