Article ID Journal Published Year Pages File Type
1483020 Journal of Non-Crystalline Solids 2010 5 Pages PDF
Abstract

Glass melts with the basic mol% composition 26 Na2O · x Al2O3 · (74 − x) SiO2 (x = 5, 10, 15 and 20); x Na2O · 10 CaO · 10 Al2O3 · (80 − x) SiO2 (x = 10, 15, 20 and 25) and x Na2O · 20 Al2O3 · (80 − x) SiO2 (x = 10, 15 and 20) doped with 1 mol% CuO were studied by means of square-wave voltammetry in the temperature range from 800 to 1150 °C. Each voltammogram shows two distinct maxima. The first maximum occurs at potentials in the range from −100 to + 150 mV and is caused by the Cu+/Cu2+-redox pair. The second maximum is observed at more negative potentials and is due to the Cu+/Cu0-redox transition. With decreasing temperature both peaks are shifted to more negative (or less positive) values. From the linear dependency of the peak potentials upon the temperature ΔH°, ΔS° and the Cu+/Cu2+-redox ratio at 1000 °C were calculated. Furthermore the effect of the glass composition on the Cu+/Cu2+-redox equilibrium was discussed with respect to the melt structure and the incorporation of the copper ions into the alumosilicate network.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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