We propose a simple model of glass formation for various types of covalent and network glasses: binary covalent glasses, with the composition denoted by XnYm + x MpYq, with X an element of III-rd or IV-th group (e.g. B, Al, or Si, Ge), while MpYq is an alkali oxide or chalcogenide; next, the covalent network formers of the type AxB1-x, e.g. Gex Se1-x, Six, Te1-x etc. Finally, certain ternary glasses, with two different modifiers present, are also discussed. A simple formula relating the glass transition temperature Tg to the modifier consentration is derived. We give examples which show a good agreement of our formula with the experimental data.
Richard Kerner and Matthieu Micoulaut