Diffusion: Introduction and Case Studies in Metals and Binary Alloys -- The Elementary Diffusion Step in Metals Studied by the Interference of Gamma-Rays, X-Rays and Neutrons -- Diffusion Studies of Solids by Quasielastic Neutron Scattering -- Diffusion in Semiconductors -- Diffusion in Oxides -- Diffusion in Metallic Glasses and Supercooled Melts -- Fluctuations and Growth Phenomena in Surface…