High temperature thermoelectric properties of CoSb₃ skutterudites with PbTe inclusions

Caroline Chubilleau (1, 2) , Bertrand Lenoir (2) , Philippe Masschelein (2) , Anne Dauscher (2) , Christophe Candolfi (2) , Emmanuel Guilmeau (3) , Claude Godart (4)

1 LITEN - Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux
2 IJL - Institut Jean Lamour
3 CRISMAT - Laboratoire de cristallographie et sciences des matériaux
4 ICMPE - Institut de Chimie et des Matériaux Paris-Est

Nanostructured thermoelectric materials generally exhibit enhanced properties. PbTe-CoSb₃ thermoelectric composites (0-8 wt% of PbTe) have been successfully prepared by freeze-drying nanoparticles of PbTe (6 nm in diameter, synthesized by laser fragmentation of micron-sized particles in water) with micron-sized skutterudite CoSb₃ powders (around 5 µm in diameter, synthesized by powder metallurgy), followed by spark plasma sintering. X-ray diffraction analyses and scanning electron microscopy observations have been performed. Microstructures reveal an agglomeration of the PbTe particles at the grain boundaries of CoSb₃. Electrical resistivity, thermopower, and thermal conductivity measurements have been performed in the 300-800 K temperature range. The composites exhibit n-type conduction whereas the reference CoSb₃ skutterudite is p-type. This change of conduction mode is attributed to substitution of Sb for a minute amount of Te in the composites. The influence of both PbTe nanoparticules and Te on the thermoelectric properties is discussed in detail.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Matériaux

Caroline Chubilleau, Bertrand Lenoir, Philippe Masschelein, Anne Dauscher, Christophe Candolfi, et al.. High temperature thermoelectric properties of CoSb₃ skutterudites with PbTe inclusions. Journal of Materials Science, 2013, 48 (7), pp.2761-2766. ⟨10.1007/s10853-012-6891-3⟩. ⟨hal-01288552⟩