Conductivity data which ranged from direct-current to mid-infrared frequencies were obtained at various temperatures. It was found that the spectra exhibited 2 new dynamic features. One of these was a thermally activated Debye-type relaxation which was attributed to the frequent hopping of Ag ions from their normal lattice sites to adjacent interstitial sites and back again. Another feature was a contribution to the conductivity, up to about 1THz, which was attributed to high-amplitude vibrational motions; mainly of Ag ions. A neutron scattering study of AgBr also revealed thermally activated quasi-elastic components that were due to localized back-and-forth cation hopping and to rapid correlated movements of neighboring ions.

K.Funke, D.Wilmer, T.Lauxtermann, R.Holzgreve, S.M.Bennington: Solid State Ionics, 1996, 86-88[1], 141-6