Structure of Glass Forming Halides. I. Liquid Beryllium Fluoride

Abstract

Viscosity and electric conductivity measurements have been made on liquid beryllium fluoride over the temperature range 700–950°C. The high specific resistance and viscosity and the magnitude of the corresponding energies of activation indicate that the classical random network structure for glasses is applicable. Liquid BeF2, similar to liquid GeO2 and SiO2, is highly associated even at elevated temperatures. At a temperature 200° above the melting point, the energy of activation for viscous flow is greater than the heat of vaporization. The ease of glass formation is attributed to the network structure of the liquid.