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

At ISIS, RAL (UK) we have produced a pulsed ultra-slow muon beam (E≤20 eV) and performed the first μSR experiments. Thanks to the pulsed feature, the implantation time is automatically determined and, by adjusting the final muon energy between approximately 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.