A model of glass transition in binary and ternary glasses

Abstract

We propose a simple model of glass formation for various types of covalent and network glasses: binary covalent glasses, with the composition denoted by X n Y m + x M p Y q , with X an element of III-rd or IV-th group (e.g. B, Al, or Si, Ge), while M p Y q is an alkali oxide or chalcogenide; next, the covalent network formers of the type A x B 1− x , e.g. Ge x Se 1−x, Si x, Te 1−x etc. Finally, certain ternary glasses, with two different modifiers present, are also discussed. A simple formula relating the glass transition temperature T g to the modifier consentration is derived. We give examples which show a good agreement of our formula with the experimental data.