Impurity trapping effects in the localisation of muons in solids

Publisher Website
Google Scholar
Abstract
Muon spin rotation ( mu SR) experiments are now regularly used to study solids and solid-state processes. The interpretation of mu SR data is usually based on a 'standard' picture in which the muons localise randomly in the solid, and then diffuse, possibly encountering impurities. There remain some important cases where no satisfactory interpretation results. For some of these anomalous systems the authors propose an alternative picture in which the two different factors are the importance of metastable (free muon) excited states, and the role of impurities in causing localisation. They show this allows a possible explanation of results for Al:Mn and demonstrate that elastic strain fields of defects may be a major factor in influencing localisation. They also propose a new mechanism for delayed self-trapping.