Mixed-anion fluoride compounds containing highly polarizable sulfide ions are less widely reported than comparable single-anion materials and have potential use in device applications. This study reports the synthesis of Ba₁₈F₁₈In₈S₂₁ and its crystal structure analysis by X-ray diffraction and electronic structure analysis by fluorine K-edge X-ray absorption spectroscopy. The solid-phase synthesis of Ba₁₈F₁₈In₈S₂₁ using indium sulfide as starting material was superior to that using indium metal and elemental sulfur and yielded a product with comparatively little impurity. The experimental fluorine K-edge X-ray absorption near edge structure of Ba₁₈F₁₈In₈S₂₁ was well-reproduced by the first principles calculations using the CASTEP program.

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The oxidation reaction of SiO₂-supported Ni particles with the heterogeneous distribution of the oxidation state of Ni has been investigated by means of the in-situ XAFS technique. The temperature-programmed reduction of NiO was terminated to produce the mixed oxidation states of NiO and Ni(0) in a single particle. The amount of the Ni(0) species located at the particle surface was determined by the composition analysis using the XANES spectra of the partially reduced NiO particles measured before and after the O₂ exposure at room temperature. The oxidized fraction was apparently smaller than the pre-reduced Ni(0), indicating that the reduction of NiO begins at the specific surface site and the reduced region expands toward the particle core by digging into the particle. The O₂ exposure to the partially reduced NiO particle at room temperature generated the Ni(0) core surrounded by NiO.

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The double-edge DXAFS (DE-DXAFS) system was developed at BL-5 of SR Center. The DE-DXAFS apparatus covers the XANES measurements for 13 combinations of 3d transition elements by using two Si(111) polychromators with the different curvature. The way to choose a set of polychromators, the setup procedure of the DE-DXAFS apparatus, and the measured XANES spectra for the standard metal foils are discussed to judge the performance.

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Green vegetables contain relatively high amounts of calcium. To analyze the chemical species of calcium in spinach (Spinacia oleracea), Malabar spinach (Basella alba), and Komatsuna (Brassica rapa Var. perviridis), the calcium K-edge X-ray absorption near edge structures (XANES) were measured using the dried powder samples of these vegetables. The XANES of calcium carbonate, calcium lactate, ascorbic acid calcium, and calcium oxalate were used as reference spectra for comparison. The XANES of spinach and Malabar spinach were consistent with the shapes of calcium oxalate. Komatsuna was similar to the shapes of ascorbic acid calcium and calcium lactate. The electrochemical behavior of these vegetables was also examined. The oxidation peak current, which can be attributed to calcium extraction, was the largest in Komatsuna among them. The calcium K-edge XANES of Malabar spinach treated with different potentials was investigated to analyze the chemical state change of calcium species induced by electrochemical reactions, but it did not show electrochemical potential dependency.

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