Abstract
The structure of glasses in the binary system SiO2-GeO2 has been studied by Raman spectroscopy. Our results are consistent with mixing of SiO2 and GeO2 tetrahedra. The changes induced by temperature and by pressure on the structure are monitored by in situ measurements on the same mixed glasses. Anomalous temperature dependences are observed not only for SiO2 glass and GeO2 glass but also for mixed glasses. Particular attention is focused on the pressure densification mechanism in mixed glasses. Via the pressure dependence of the width of the main Raman band, we show that the compression mechanism in mixed glasses is intermediate between that of the end members.