High-Resolution X-ray Microprobe Using a Spatial Filter and Its Application to Micro-XAFS Measurements

An x‐ray microprobe system with total‐reflection mirror optics for trace element analysis has been developed at beamline 37XU of SPring‐8. To achieve sub‐microprobe, a spatial filter has been installed downstream of a monochromator. Focusing tests have been performed in the x‐ray energy range of 6–14 keV. A focused beam size of 0.83 μm(V)×1.35 μm(H) has been obtained at an x‐ray energy of 10 keV, and using a spatial filter in the horizontal direction, the beam size is down to 0.84 μm. Micro‐x‐ray absorption fine structure (XAFS) spectroscopy of submicrometer particles has been done by utilizing the total‐reflection mirror optics. It was clearly observed from the nickel K‐edge XAFS spectra that the oxidation state of nickel was a mixture of metal and oxide even in the single submicrometer particle.