Department of Engineering Materials, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
Copyright © 2008 Michael I. Ojovan. This is an open access article distributed under the
Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
An overview is given of amorphous oxide materials viscosity and glass-liquid transition phenomena. The viscosity is a continuous
function of temperature, whereas the glass-liquid transition is accompanied by explicit discontinuities
in the derivative parameters such as the specific heat or thermal expansion coefficient.
A compendium of viscosity models is given including recent data on viscous flow model
based on network defects in which thermodynamic parameters of configurons—elementary
excitations resulting from broken bonds—are found from viscosity-temperature relationships.
Glass-liquid transition phenomena are described including the configuron model of
glass transition which shows a reduction of Hausdorff dimension of bonds at glass-liquid transition.