Co-L3 X-ray absorption near-edge structure analysis of Pr1-xCaxCoO3-δ and Pr1-xSrxCoO3-δ

The valence state of Co ions in Pr1-xCaxCoO3-δ and Pr1-xSrxCoO3-δ has been investigated by an analysis of the Co-L3 X-ray absorption near-edge structure (XANES) profile. The observed intensity distributions of Co-L3 XANES change continuously with increasing concentration of alkaline-earth ions. To investigate the origin of this change in the XANES profile, charge transfer multiplet calculations were carried out, which could successfully explain the change in the spectral profile; they also suggest that the valence state of Co ions in Pr1-xCaxCoO3-δ and Pr1-xSrxCoO3-δ is between 3+ and 4+ and increases gradually with the concentration of alkaline-earth ions.