Structure and Ionic Conduction in(AgI)x(AgPO3)1−xGlasses

The relation between fast ion conductivity, glass forming ability, and structure in ${\left(\mathrm{AgI}\right)}_x{\left(\mathrm{AgP}{\mathrm{O}}_3\right)}_{1-x}$ glasses has been studied using neutron and x-ray diffraction and extended x-ray-absorption fine structure spectroscopy. Reverse Monte Carlo models based on the data show that AgI doping causes an increase in free volume available for ${\mathrm{Ag}}^{+}$ motion, which leads to the considerable increase in conductivity but also limits the glass forming range by decreasing ionic cross-linking of the phosphate network. Analysis of the available free volume shows a percolation transition in the connectivity of ${\mathrm{Ag}}^{+}$ pathways for $0.2<x<\mathrm{}0.3\mathrm{}$.