Muon spin relaxation study of the (FμF)− ion in magnetic fluorides

A positive muon implanted in a solid fluoride insulator can form a hydrogen-bonded (FμF)− ion, in which the nuclear magnetic interactions cause a distinctive zero-field (ZF) muon spin relaxation (μSR) signal. In a fluoride material in which the anions have electronic magnetic moments, the muon’s interaction with nearby 19F nuclear moments must compete with its interaction with more distant but much larger anion moments. We report observation of …