Position and Dynamics of Ag Ions in Superionic AgI Using Extended X-Ray Absorption Fine Structure

Abstract

By use of extended x-ray absorption fine structure, the Ag ions in superionic AgI are shown to occupy the distorted tetrahedral sites in the iodine bcc lattice, being slightly displaced from the center toward the faces along the most probable diffusion path. The residence time of the Ag ions in these sites is determined to be longer than their flight time, implying that the jump-diffusion model is more appropriate than a free-diffusion model.