4d Electronic structure analysis of ruthenium in the perovskite oxides by Ru K- and L-edge XAS

The 4d electronic structure of ruthenium in the perovskite oxides, La₂MRu^IVO₆ (M = Zn, Mg, and Li) and Ba₂YRu^VO₆, has been investigated by the Ru K-and L-edge XANES and EXAFS analyses. Such X-ray absorption spectroscopic results clarify that the Ru^IV (d⁴) and Ru^V (d³) ions are stabilized in nearly regular O_h site. Comparing the Ru L-edge XANES spectra of perovskites containing isovalent ruthenium, it has been found that the t_2g state is mainly influenced by A site cation, whereas the e_g is mainly affected by neighboring B site cation. The experimental EXAFS spectra in the range of R ≤ ∼4.5 Å are well reproduced by ab-initio calculation based on crystallographic data, which supports the long-range structure presented by Rietveld refinement.