Ion dynamics and transition to the superionic state in β-AgI

By measuring the nuclear spin-lattice relaxation time of ¹²⁷I cooperative effects in Ag diffusion have been found which point to the necessity to include mutual cation interaction in the diffusion theory. An anomalous increase of the relaxation rate within 5 K just below the transition into the superionic state is taken as dynamical evidence for a discontinuity in the number of diffusing Ag ions, i.e. for sublattice melting.