Electronic Structures of LaCoO₃-Based Oxides Studied by Soft X-ray Absorption Spectroscopy under Controlled Temperatures and Oxygen Partial Pressures

Abstract

In situ soft X-ray absorption spectroscopic measurements were performed to evaluate electronic structures of LaCoO3. X-ray absorption spectra at Co L II- and L III-edges were measured under p(O2) = 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 Co3+ 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.