Imaging Cross Section of X-ray Multilayer Mirror by Scanning Tunneling Microscope

Multilayers are used in x-ray optics as mirrors.1 They usually consist of a stack of bi-layers of two different materials. For x-ray optics, the thickness of the bi-layer, or the d-spacing of the multilayer, ranges from 2 nm to 20 nm. Since x-ray multilayers are usually made by evaporation or sputtering technique, most of materials in multilayers are amorphous or polycrystalline.