Grazing-incidence Diffraction and Small angle X-ray scattering

X-ray grazing incidence diffraction and small angle scattering are a scattering method which combines out-of plane reflectivity under the condition of X-ray total external reflection with in-plane Bragg diffraction and small angle scattering, respectively. The formation of an evanescent wave propagating parallel but close below the sample surface opens the possibility to probe structures at a sample surfaces or close below it.