Diffraction of evanescent x-rays: Results from a dynamical theory

Evanescent x-rays can be made to diffract from periodic structures parallel to a surface or interface. A dynamical theory of diffraction yields several novel predictions which may be experimentally important. First, x-ray standing-wave fields are generated and can be controlled. This suggests a new technique for unambiguous determination of surface structure. Secondly, evanescent x-ray wave fields may be produced in the incident medium as well as the substrate. Finally, the rocking curve of the diffracted beam is narrow and asymmetric.