Asymmetric F-μ-F interaction of the muon in polyfluorocarbons

The muon can be used to study the strong F-H-F bond in many chemicals including fluorine. In various metal fluorides a characteristic spin relaxation function has already been reported due to a symmetric F-μ-F bond and nuclear dipole coupling from the two neighboring fluorine nuclei. We have observed an asymmetric F-μ-F or μ-F bond in various 'Fluorinert' compounds below the freezing temperature. On the other hand in 'Teflon' we found strong F-μ-F signals at low temperature