In-situ Simultaneous Soft X-ray Absorption and Emission Spectroscopy under Controlled Atmosphere and Temperature

Abstract

In-situ simultaneous measurement technique of soft X-ray absorption and X-ray emission spectroscopy, which was available for atmospheric pressure and high temperature, was developed. This technique is expected to provide direct information about electronic structures, both occupied and unoccupied pDOS, of functional materials under controlled atmospheric and temperature conditions. In this work, this technique was applied to simultaneously measure O K-edge X-ray absorption and X-ray emission spectra of LaCoO₃-based oxides under various oxygen partial pressure and temperatures. Clear O K-edge spectra could be obtained even in 1 bar of 100 ppm O₂-He, 0.1%O₂-He and 1%O₂-He atmospheres below 873 K. The changes of the O K-edge X-ray absorption and X-ray emission spectra due to the changes of oxygen partial pressure and temperature were discussed in terms of changes of defect concentrations and spin states of the oxides. Availability of the developed in-situ simultaneous spectroscopic technique was successfully demonstrated.