Production of pulsed ultra slow muons and first mu SR experiments on thin metallic and magnetic films

At ISIS, RAL (UK) we have produced a pulsed ultra-slow muon beam (E less than or similar to 20eV) and performed the first mu SR experiments. Thanks to the pulsed feature, the implantation time is automatically determined and, by adjusting the final muon energy between similar to 8 keV and 20 eV, depth slicing experiments are possible down to monolayers distances. We report slicing experiments across a 20 nm copper film on quartz substrate with evidence for a 2 nm copper oxide surface layer. A preliminary experiment on a hexagonal cobalt film suggests the existence of muon precession in the local magnetic field. (C) 2000 Published by Elsevier Science B.V. All rights reserved.