X-ray absorption study of perovskite PrSrCoO

Matsumura, Daiju   ; Yoshii, Kenji  ; Tsuji, Takuya  

The perovskite-type oxides RACoO (R: rare earths, A: alkaline earths) have been extensively studied owing to a variety of many kinds of possible applications as well as their peculiar physical properties. A recent investigation proposed that PrSrCoO is suitable for solid oxide fuel cells on the basis of its high electrical conductivity and excellent cell performance. In this study, we have performed X-ray absorption measurements using synchrotron radiation to reveal details of the electronic and crystallographic structures of this system. We have observed local structures around Co from extended X-ray absorption fine structure spectra. It was found that the Debye-Waller factor increased with increasing x up to 0.2-0.3, while it is almost unchanged for x larger than 0.2-0.3. This result suggests importance of static distortion on the electrical properties of this system.