Fluctuation volume of amorphous materials in the model of delocalized atoms.

A concept in accordance with which the formation of a hole in amorphous substance corresponds to delocalization of atom is developed. It is shown that the fractions of fluctuation volume calculated using the viscosity data and the dependence of the glass-transition temperature on the cooling rate of melt are identical at a conventional cooling rate of 3 K/min. The Bartenev equation is applied in the study of oxygen-free glasses. [ABSTRACT FROM AUTHOR]