Diffusion in crystalline materials

Recently nuclear scattering of synchrotron radiation proved to be a powerful new method to study the elementary diffusion jump in crystalline solids. The scattered radiation decays faster when atoms move on the time scale of the excited-state lifetime of a Mössbauer isotope because of a loss of coherence. The acceleration of the decay rate differs for different crystal orientations relative to the beam providing information not only about the rates but also about the directions of the elementary jumps. We discuss first applications of the method.