Tecnique

About the technique

Small Angle X-ray Scattering (SAXS) is a technique in which the elastic diffusion of X-rays from a sample with electron density inhomogeneities of the order 1-100 nm is measured at low angles (typically 0.1-10°). This angular interval contains information about the shape, the size, or the characteristic distances of these inhomogeneities.

In practice by means of SAXS analysis it is possible to obtain structural information about macromolecules or colloidal aggregates in solution, characteristic distances in partially ordered samples in the form of liquids, gels, pastes and powders, size of pores of porous materials, correlation lengths in networks....

By extending the angular range also at larger angles (Wide Angle X-Ray Scattering, WAXS), information about characteristic distances below 1 nm becomes available, which can provide at the same time insights into the internal sub-nanometer scale structure of the samples.

The possibility to perform experiments in reflection geometry (Grazing Incidence SAXS, GISAXS) extends the application also to the characterization of surfaces structured at the nano and meso-scale.

The scattering techniques provide information which is averaged and representative of a macroscopic portion of the sample and the relatively simple experimental setup has the big advantage of requiring minimal and simple sample preparation of the samples to be analyzed, making it possible to characterize a system as a function of several experimental parameters.