Muons as Light Hydrogen Probes–Diffusion and Trapping

ABSTRACTContributions of the muon spin rotation technique (μSR) to metal physics problems are surveyed. The similarity between the muon and the proton constitutes μSR as a new tool to investigate the physics of H–like interstitials on an atomic scale. Experiments on the lattice location and on local properties like the Knight shift as well as diffusion measurements are reviewed. In particular the extreme sensitivity of muons toward impurities and lattice defects is emphasized. Results on the trapping of muons by substitutional impurities or vacancies in the ppm range are displayed.