A Neutron and X-Ray Diffraction Investigation of Intermediate Range Structure in Silver Borate Glasses

The ion diffusion mechanism in ion conducting glasses has in many reports been suggested to be linked to the structure. However, in most cases the structures of the glasses are not very well known. We have investigated the structure of the glass system (AgI)(x) (Ag(2)O-2B(2)O(3))(1-x), with x=0, 0.6 by neutron and x-ray diffraction experiments. AgI doping produces an intense peak in the neutron data at an anomalously low Q-value (0.8 angstrom(-1)) that indicates increased intermediate range ordering. Only a weak peak is observed at a similar Q-value in the x-ray structure factor. By comparing the different neutron and x-ray weighting factors the origin of the anomalous peak is unambiguously attributed to correlations within the B-O network. The experimental results have been used to model the glasses by Reverse Monte Carlo simulations to obtain more detailed views of the structures.