Diffusion path and Haven’s ratio of mobile ions inα-Ag2Te

A molecular-dynamics method is applied in a study of silver diffusion in superionic conductor ${\mathrm{Ag}}_2$Te for several temperatures with use of effective pairwise potentials. The static and dynamical structures are calculated. The density distribution map of silver ions suggests that a Ag ion, located at a tetrahedral site for most of the time, moves to a neighboring tetrahedral site via the vicinity of an octahedral site—a result which is consistent with the explanation of Haven’s ratio proposed by Okazaki. The activation energy for a ionic diffusion also is obtained from the Arrhenius plotting of the self-diffusion coefficient of ${\mathrm{Ag}}^{+}$.