Résumé
100 years have passed since the discovery of x-ray diffraction by von Laue, Knipping andFriedrich.The scientific world owes a lot to Röntgen for the discovery of x-rays in 1895 andwith the research efforts of W L and W H Bragg in 1912, the concept of Bragg’s law andinterpretations given by P P Ewald, saw the birth of the wonderful field of crystallography.Today, the scientific world sees the various tools delivered by this powerful technique asindispensible, whether it concerns the development of advanced high-tech materials or thestructural understanding of biological molecules or drug design. Diffraction and associatedmethods for structure analysis at the atomic scale are developed into powerful fingerprintmethods, and have become the backbone of industry for quality inspection on one hand, andon the other hand, stand at the forefront of materials characterization in research laboratory.Beyond these characterization tools available at laboratory level, large scale facilities(LSF) and notably the neutron and synchrotron radiation sources became increasinglyimportant during the last decades. Diffraction with neutron or synchrotron radiation isvery complementary, as outlined below: Neutrons have the corresponding wavelengths andenergies directly related to interatomic distances and lattice dynamics. Thus, neutron scatteringenables simultaneous access to both structure and dynamics of any type of materials.Neutrons also have a magnetic moment allowing direct characterization of the magneticstructure of materials at the microscopic scale. The possibility to easily vary the contrast ofa single element using its different isotopes renders the neutron to be an irreplaceable toolin chemistry, solid state physics, biology and soft matter. Then, having no electric charge,neutrons can easily penetrate materials without significant absorption, allowing a nondestructivecharacterization even on large volume fractions