| Silver ion transport in Se-rich Ag-Ge-Se glasses is the basis for applications as (1) solid electrolytes and (2) photoresists in microelectronics. In this thesis, anomalous X-ray scattering was used to determine the structure of a representative glass, with a composition 0.25Ag-0.75GeSe;The glass was prepared by quenching the melt. The preliminary characterization of the glass included determining the glass transition temperature and the density. The complex impedance/admittance method was used to measure the ionic conductivity between ;Anomalous scattering experiments were performed using synchrotron radiation. The differential anomalous scattering method was used to obtain the difference distribution functions around each component of the glass. Large background intensities from resonant Raman scattering and, in some instances, fluorescence were present in the experiments. Equations for calculating the absolute intensities of these processes were presented and used in planning and analyzing the experiments.;The partial distribution functions were calculated using the approach described by D. T. Keating. The method was extremely sensitive to experimental error because ill-conditioned systems of equations were solved. An alternative method, based on the maximum entropy principle, was explored. The method estimated the partial distribution functions from the available data while explicitly treating the presence of experimental error. The results from the Keating approach were not interpretable, but those from the maximum entropy method were realistic and consistent in most ways with the results from the difference approach.;The structural results show that Ge is tetrahedrally coordinated by Se and retains its network forming character. The quality of the difference distribution function around Ag was uncertain due to adverse experimental conditions. A reasonable interpretation is that Ag is coordinated by 4.6 Se atoms and that few Se-Se bonds exist. Short Ag-Ag distances (about 3.3 A) possibly exist. The mobility of Ag ions is closely linked to their low coordination and possible cooperative interactions. |
