Résumé : Increasingly materials with structural and dynamics disorder are studied with crystallographic methods, which were considered for many years only able to show perfectly periodic arrangements. In reality, this perfect periodicity simply describes an average reconstruction of the structure and the disorder adds a supplementary signal, found as diffuse scattering. The analysis can be helped with a look to the real space, using the Pair distribution function, modelling the disorder with Montecarlo methods and so on. This talk will explore different cases giving an emphasis on the design of the materials, the use of advanced total scattering techniques and the link to functional properties.
