Dynamic Aspects of Frenkel Defect Formation in Silver Chloride and Silver Bromide

Abstract

ABSTRACTComplete ionic conductivity spectra have been taken of solid silver chloride and silver bromide at various temperatures. The spectra contain two new dynamic features: i) a thermally activated Debye-type relaxation which is explained by the frequent hopping of silver ions from their regular lattice sites to adjacent interstial sites and back again, and ii) conductivity maxima at about 500 GHz which are attributed to high-amplitude individual vibrational motions, mostly of the silver ions. – We also report results of a neutron scattering study on silver bromide. These contain thermally activated quasielastic contributions caused by the localized cation back-and-forth hopping and also give evidence of fast correlated movements of neighboring ions.