@article{6b6c44a0e6f011ddb0a4000ea68e967b,
title = "Electrical conductivity and viscosity of borosilicate glasses and melts",
abstract = "Simple sodium borosilicate and silicate glasses were melted on a very large scale (35 l Pt crucible) to prepare model glasses of optical quality in order to investigate various properties depending on their structure. The composition of the glass samples varied in a wide range: 3 to 33·3 mol% Na2O, 0 to 62·5 mol% B2O3, and 25 to 85 mol% SiO2. The glass samples were characterised by different methods. Refractive indices, density and thermal expansion were measured. Phase separation effects were investigated by electron microscopy. The electrical conductivity of glasses and melts were determined by impedance measurements in a wide temperature range (250 to 1450°C). The activation energies were calculated by Arrhenius plots in various temperature regions: below the glass transition temperature, Tg, above the melting point, Tl, and between Tg and Tl. Viscosity measurements were carried out with different methods from Tg to the melt. The measured data were fitted and the activation energies calculated. Simple exponential behaviour was found only in very narrow temperature ranges. The effect of B2O3 in sodium borosilicate glasses and melts is discussed in comparison with sodium silicate glasses and melts.",
keywords = "Glkass Melt viscosity, electrical conductivity, sodium borate, silicate",
author = "Doris Ehrt and Ralf Keding",
note = "Volumne: 50; International Conference on Borate Glasses, Crystals and Melts (BORATE2008) ; Conference date: 18-08-2008 Through 22-08-2008",
year = "2009",
language = "English",
volume = "50",
pages = "165--171",
journal = "Physics and Chemistry of Glasses-European Journal of Glass Science and Technology Part B",
issn = "1753-3562",
publisher = "SGT- Gesellschaft Society of Glass Technology (Sheffield, UK)",
number = "3",
}