Muon-spin spectroscopy in selenium

In recent years, the positive muon, used as a chemical analogue of the proton, has proven of great value in studies of the behaviour of hydrogen defects in semiconductors, especially the Group IVA elements Si and Ge. In the present work we explore the application of the mu SR techniques to the Group VIA semiconductors S and Se, reporting new data for Se and comparing these with previous data for S. The chemical species formed following muon implantation include two paramagnetic centres, namely atomic muonium and a molecular radical, together with one or more muon states which appear electronically diamagnetic. The reaction schemes are evidently similar in the two elements although there are significant quantitative differences in the kinetics. The very close similarity in the muon-electron hyperfine constants of the radical states tends to support their assignment to the simple diatomic species SeMu and SMu, close relatives of the hydroxyl radical OH. Copyright (C) 2000 John Wiley & Sons, Ltd.