We discuss the scattering of X-rays from thin films at a surface or interface decorated with a morphology of islands and how these effects manifest themselves in the specular reflectivity and the diffuse (off-specular) scattering. We show how this technique has been used to study block copolymer films decorated with islands on the surface and the development of electrochemically induced pitting on a Cu electrode in an electrolyte solution.
The availability of synchrotron radiation has made it possible to study in detail the in situ structure and morphology of films absorbed on solid or liquid surfaces. Specular X-ray reflectivity studies have been used to study the laterally averaged density profile of the films along the surface-normal direction, and off-specular scattering and grazing incidence diffraction have been used to study the in-plane structure. Scattering methods are in a sense complementary to various types of surface imaging microscopies, such as AFM, STM, etc., but have the advantage of being able to provide global statistical information about the surface without the need for digitizing and averaging the images.