A THEORETICAL-MODEL OF FORMATION OF COVALENT BINARY GLASSES .1. GENERAL SETTING

A general statistical model of growth for amorphous structures based on a few simple assumptions are presented. First stable structural units in a supercooled liquid are chosen and a variable is attributed to each of these elementary configurations, which describes the probability of finding it among all other agglomerates with the same number of atoms. The evolution of these probabilities in time leads to a system of first-order differential equations describing these processes. Its singular solutions can be identified with glassy amorphous states. With a few parameters fixed, which are generally the binding energies for the covalent bonds between the structural units (referred to as singlets), the stationary solutions are obtained for the system. These give the statistics of structural entities which exist for different modifier concentrations and lead to a prediction of the glass transition temperature.