Investigating structures at the nano scale

The exceptional properties of synchrotron radiation: high flux, possibility of varying the wave-length, coherence, polarization, have allowed spectacular advances in the structural analysis of condensed matter. This document gathers 5 short articles that illustrate the great diversity of the results: the first article deals with the crystallography of biological molecules that opens the way to studying the relationship between the shape of the protein and its functioning, the second article presents the study of magnetism of multi-ferroic materials with the help of X-rays, the third article describes how X-ray coherent diffraction can reveal deformations and topological defects of crystals, the fourth article shows how grazing incidence techniques shed light on the organisation of surfaces, interfaces or nano-structures, the last article presents the potentiality of the synchrotron radiation for studying the behaviour of matter under extreme conditions of pressure and temperature. (A.C.)