The project covers experimental studies of defects in metals and ceramics on an atomic scale. Structural as well as functional properties of materials are significantly determined by the presence and the behavior of atomic defects such as vacancies, dislocations, and grain or phase boundaries. For the characterization of such defects and the atomic processes they are involved in, two specific and complementary experimental approaches are used. From an atomistic point of view techniques are used that utilize the positron-electron annihilation in solids; from a more mesoscopic, continuum mechanics based experimental approach, high-resolution dilatometry is applied. The techniques for these two experimental approaches are also further continuously developed and applied and specifically tailored to novel classes of materials emerging in recent years such as metallic glasses, perovskite-based electro ceramics and advanced ionic conductors for application in batteries.