Chemical properties and thermopower of the new series of skutterudite Ce1-pYbpFe4Sb12

We report on sample preparation and electron microprobe analysis in the series Ce1-pYbpFe4Sb12 that shows that a solid solution exists between CeFe4Sb12 and YbFe4Sb12 for all compositions in the series. The valence states of Ce and Yb have been studied using X-ray absorption spectroscopy. Ce is trivalent throughout the series, whereas the Yb valence linearly changes from 2.16 for Yb0.93Fe4Sb12.08 to 2.71 for Ce0.85Yb0.05Fe4Sb12.06. The Seebeck coefficient was measured from 4 K to room temperature. It is enhanced by more than 20% at room temperature in Ce-Yb mixed compounds as compared to CeFe4Sb12 or YbFe4Sb12. (C) 2002 Elsevier Science B.V. All rights reserved.