Planar rings in vitreous silica

Abstract

An energy minimization argument shows that 2- and 3- fold rings of SiO bonds in vitreous silica can be expected to be quite planar. Evidence supporting the existence of planar 3-fold rings is found in the sharp line at 606 cm −1 in the Raman spectra. The method of argument is general, and suggests that similar sharp Raman lines reported in several other glasses may signify the existence of small planar rings in concentrations sometimes greater than 1%.