Abstract: We have selected Cr and C as a material pair of multilayer (ML) mirrors for soft x rays at the wavelength near 5 nm. The Cr-C ML structures have successfully been fabricated with rf-magnetron sputtering. The ML structures have been characterized with transmission electron microscopy (TEM), x-ray diffraction, and reflectivity measurement by SR light. From the observation of TEM images, Cr-C MLs had uniform and less-defective layered structures with the d-spacing down to 2.4 nm. Reflectivities at normal and grazing incidence were remarkably decreased with decreasing the ML d-spacing. Normal incidence reflectivity at 5 nm was as high as 7%. The regularity of the d-spacing of the MLs was evaluated with a moire image that was formed by putting a reference stripe pattern on the cross-sectional TEM micrograph. Compared to Ni-C MLs, Cr-C is a preferable material combination for x-ray mirrors for shorter wavelength and normal incidence. !9
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