Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1484340 | Journal of Non-Crystalline Solids | 2008 | 6 Pages |
Abstract
Glasses with the base mol% composition xNa2O · 10CaO · (90 â x)SiO2 with x = 10, 16, 20 and 26 were investigated at high temperatures using square-wave voltammetry. The recorded voltammograms exhibit two peaks. That at less negative or (depending on temperature and glass composition) even positive potential is attributed to the reduction of Cu2+ to Cu+, while that observed at more negative potential is caused by the reduction of Cu+ to metallic copper. For both redox steps, the peak potentials decrease linearly with temperature. Those of the composition with 10 mol% Na2O show the most negative values. The diffusion coefficients can be fitted to Arrhenius equation. If referenced to the same viscosity, the diffusion coefficients decrease with increasing Na2O-concentration. The effect of composition on the thermodynamics as well as on diffusivities is explained by the incorporation of the copper ions into the melt structure.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Juliane Kaufmann, Christian Rüssel,