Intermediate Range Order in Tellurite Glasses Due to Modifier Ion Clustering. Josef W. Zwanziger Dept. of Chemistry Indiana University Bloomington, IN 47405

The structure of tellurite glasses changes substantially as modifiers such as alkali oxides are added. We show how the spatial distribution of sodium ions in sodium tellurite glasses develops significant intermediate range order at higher sodium concentrations, with a length scale maximum at the composition coinciding with the stability maximum of this glass system. Our results are based on spin-echo nuclear magnetic resonance measurements and neutron diffraction results. Finally, we will comment on the relation of these results to the fragility of tellurite liquids.