Electronic Structures of LaCoO_3-Based Oxides Studied by Soft X-ray Absorption Spectroscopy under Controlled Temperatures and Oxygen Partial Pressures

摘要

In situ soft X-ray absorption spectroscopic measurements were performed to evaluate electronic structures of LaCoO_3. X-ray absorption spctra at Co L_Ⅱ- and L_Ⅲ-edges were measured under p(O_2) = 10~(-4) bar at room temperature to 873 K. Depending on temperature, the shape and the peak energy of the absorption spectra were varied, indicating thermally induced spin state transition of Co~(3+) ion. The results demonstrated that our in situ soft X-ray absorption technique is an useful tool to investigate the electronic structures of components for solid oxide fuel cells under operating conditions.