Examination of CeFe4Sb12 upon exposure to air: Is this material appropriate for use in terrestrial, high-temperature thermoelectric devices?

The rare-earth (RE) filled skutterudites (e.g., CeFe4Sb12) have been proposed for use in the next-generation of high-temperature thermoelectric devices. In this investigation, the influence of air exposure on the stability of CeFe4Sb12 has been studied for temperatures ranging from 300 K to 1073 K. Examination of the material after exposure to air at these temperatures using thermogravimetric analysis, powder X-ray diffraction, and X-ray absorption near-edge spectroscopy has shown that above 573 K, CeFe4Sb12 decomposes and then rapidly oxidizes. This temperature is much lower than the maximum operating temperature proposed for high-temperature thermoelectric devices used to recover the waste heat from vehicle exhaust systems (700-773 K).