Thermoelectric properties of the new skutterudites (Ce-Yb)/sub y/Fe/sub 4-x/(Co/Ni)/sub x/Sb/sub 12/

Polycrystalline p-type and n-type skutterudites belonging to the family (Ce-Yb)/sub y/Fe/sub 4-x/(Co/Ni)/sub x/Sb/sub 12/ have been synthesized using a standard arc-melting method and subsequent annealing. They have been characterized using X-ray diffraction (XRD) and electron probe microanalysis (EPMA). Yb valence state was estimated using X-ray absorption spectroscopy (XAS) at the Yb L/sub 3/ edge which evidences an evolution of the Yb mixed valence state in the various series. Thermoelectric properties have been investigated between 120K and 800K by mean of thermopower and electrical conductivity measurements.