The diffusion of protons in the superionic conductor CsHSO4by quasielastic neutron scattering

The diffusion of protons in the superionic phase of CsHSO 4 was investigated by quasielastic neutron scattering (QNS) on the IRIS spectrometer at the pulsed spallation neutron source ISIS, Rutherford Appleton Laboratory, UK. Two processes with different characteristic times could be distinguished: long-range translational diffusion with a diffusion coefficient D=(1.00-1.17)*10 -7 cm 2 s -1 (for a temperature range from 423 to 448 K) and jump rotation of HSO 4 groups between two possible orientations, the corresponding nonequivalent proton sites being 2.3 AA apart.