Short-range order in mesoscale systems probed by X-ray grating interferometry

The dark-field signal obtained with X-ray grating interferometry combines the object's small-angle scattering auto-correlation function with an imaging modality. Here we report on the measurement of such correlation functions with a laboratory X-ray system. By fitting a theoretical model to the data we are able to determine the size and short-range order of the scattering structures. Thus, a quantitative interpretation of the dark-field signal is also possible with a polychromatic and divergent beam. We further show how the microscopic information is obtained for mesoscale objects and can be represented in order to overlay the microstructural information on top of the macrostructure. The quantitative real-space information on the form and structure factor makes this technique highly attractive for materials science as it allows one to study these properties in the laboratory.