Development of Simultaneous Measurement System for X-ray Absorption Spectra at Two Absorption Edges

Abstract

Dispersive X-ray absorption fine structure (DXAFS) spectroscopy is a versatile measurement technique for analyzing chemical reactions in real time. We have developed a novel time-resolved DXAFS instrument based on two polychromators and a wide-range position-sensitive detector that permits direct observation of the synergistic effects of two elements. This system enables simultaneous acquisition of the X-ray absorption spectra for two different elements without any mechanical movement of the X-ray optics. The developed system was successfully applied to monitor both the synthesis of a Ni-Cu bimetallic catalyst, which revealed that the reduction of Ni occurred at a higher temperature than that of Cu, and the charge-discharge processes of a LixNi0.5Mn1.5O4-based lithium-ion battery, which demonstrated that the redox reactions of Ni and Mn occurred sequentially at specific electrode potentials.

Simultaneous two-color X-ray absorption spectroscopy using Laue crystals at an inverse-compton scattering X-ray facility

“…Also, the measurement condition cannot be optimized independently for each element. Another dispersive XAS system utilizing two polychromators was recently reported (Katayama et al, 2020). The setup is more sophisticated than the previous ones: the incident X-ray is first split by a double-hole mask and then dispersed separately by two polychromators.…”