Atomistic insights into germanosilicate glasses

Abstract

Glasses composed of silica (SiO₂) and germania (GeO₂) have significant applications in the fabrication of optical fibers. Molecular dynamics (MD) simulations based on morse potentials are employed to investigate the structural, thermal, and elastic properties of the germanosilicate(SG) glasses. The composition of the binary oxide system (GeO₂)_x- (SiO₂)_1-x varies from pure SiO₂ to pure GeO₂, where x is the mole fraction of GeO₂ ranging from 0 to 1. The structure of SG glasses is predominantly composed of four-fold coordinated tetrahedral units of SiO₄ and GeO₄. SG glasses exhibit only bridging oxygen atoms in their network structure. The concentration of Si-O-Ge bonds in the SG glasses reaches a maximum at 50 mol% GeO₂ and then declines for higher GeO₂ contents. As GeO₂ content increases, the elastic constants exhibit a downward trend.