Structural studies on superionic glass AgIAg<inf>2</inf>OV<inf>2</inf>O<inf>5</inf>

An amorphous thin plate with composition (mol%) 50%AgI-30%Ag2O-20%V2O5 was prepared by rapid quenching from the melt. An EXAFS study at the Ag K-edge shows rAg-I = 2.87 A ̊, nAg-1, where nij is the coordination number, and the difference between two close AgO distances ΔrAg-O = 0.37 A ̊. X-ray RDF studies yield similar values of Ag-I = 2.96 A ̊, nAg-I = 1.3 and ΔrAg-0 = 0.37 A ̊. On theother hand X-ray RDF studies yield two V-O interactions with distances 1.78 and 2.39 Å and their coordination numbers are 3.6 and 1.7, respectively. Silver ions form bonds and secondary interactions with the network non-bridging and bridging oxygen atoms and I- ions surround the Ag+ ions. The results favour a model of dispersed Ag+ and I- ions in the glass rather than the presence of clusters of microdomains of AgI in the glass. © 1989.