On the Structure of Silicate Glasses

Abstract

The diagram of the molecular refractien of Na₂O–SiO₂ glasses vs. composition (Na₂O mol%=x) is found to be linear with breaks at x=0.231, 0.333, 0.428 and 0.474. Analysing this fact, it is concluded that at the latter three breaks the glass has the similar local arrangement of SiO₄ tetrahedra as the silicate crystals do, which was found before by the author on X-ray and viscosity. The break at x=0.231 is briefly discussed. By the introduction of Na₂O or other oxides into SiO₂ glass, “ solvation ” takes place, and also “solvation in refractivity” —dec rease of refractivity of SiO₄ tetrahedra—takes place.
These effects by the various metal ions are summarized and the characteristics of ions in gases or aqueous solutions are found to be preserved to some extent also in the silicate glasses.