Intermediate-range order in vitreous SiO and GeO

Kohara, Shinji*; Suzuya, Kentaro

The total structure factors, S(Q), obtained from high-energy X-ray and neutron diffraction measurements on vitreous SiO (v-SiO) and vitreous GeO (v-GeO) have been analysed by the reverse Monte Carlo (RMC) modelling technique to generate a three-dimensional structural model. The bond angle distributions and the ring size distributions from the model indicated that the sixfold ring and six- and sevenfold rings are dominant in v-SiO and v-GeO, respectively. However, the fraction of threefold rings of Ge in v-GeO is larger than that of Si in v-SiO glass. These features are consistent with the published neutron diffraction and Raman scattering studies.