INCOHERENT NEUTRON-SCATTERING STUDY OF PROTONIC CONDUCTORS

Incoherent neutron scattering results are presented for two typical proton conducting systems: aqueous solutions of strong acids and fused phosphoric acid. The quasielastic profiles are analyzed in terms of mean proton translational and rotational diffusive motions. The presence and possible origin of an additional quasielastic component is then discussed in terms of proton exchange, damped oscillatory modes or collective excitations. More generally, the authors try to survey the advantages and limitations of the neutron scattering technique for a study of the proton conduction mechanism in liquids and solutions.