Use Of The Floatation Method To Investigate Structural Changes In Alkili Silicate Glasses

The authors have studied the effect of the preliminary heat treatment on the form of the density dependence on the quenching temperature for glasses of different compositions. The maximal change in density (the value of the step) increases approximately in proportion to the alkali oxide concentration, and in glasses of the composition M2O. 3SiO2 (M is La, Na or K) increases from Li to K. The activation energy of relaxation of the glass structure at temperatures below Tg was calculated from curves of the isothermal change in glass density of the methods of cross-sections. The value of E increases with temperature, and decreases with the increasing size of cation.