Synthesis and thermoelectric properties for the new partially filled skutterudite CaxCo4Sb12

Synthesis and thermoelectric properties of new partially filled Ca_xCo₄Sb₁₂ skutterudites

M. Puyet¹, B. Lenoir¹, A. Dauscher¹, M. Dehmas², P. Weisbecker², S.J. Clarke³, C. Stiewe⁴, E. Müller⁴

1Laboratoire de Physique des Matériaux, UMR7556, ENSMN, Parc de Saurupt, 54042 Nancy, France
^{2Laboratoire de Science et Génie des Matériaux et de Métallurgie , Ecole des Mines de Nancy 54042 Nancy Cedex
^{3University of Oxford, South Parks Road, Oxford, OXI 3QR, United Kingdom
^{4German Aerospace Center (DLR), Institute of Materials Research, Linder Hoehe, 51147 Cologne, Germany}}}

Materials of skutterudite structure are very promising for thermoelectric applications. Partially filled Co₄Sb₁₂ compounds have received particularly attention. Several kinds of atoms were introduced in the voids of the crystalline structure in order to decrease substantially the thermal conductivity.

It this communication, we report on the synthesis and on the transport properties of new partially filled Ca_xCo₄Sb₁₂ compounds. The synthesis has been carried out by a conventional metallurgical route. Rietveld refinement on neutron powder diffraction patterns have been performed to prove that the Ca atoms are in the voids of the structure. The filled fraction limit is found to be 0.2.

Electrical and thermal transport properties were performed in the temperature range 300-800 K. The effect of Ca on the transport properties is discussed in detail. The potential of this new family of compounds for thermoelectric applications at high temperature is also presented.