The MgO-Al2O3-SiO2 (MAS) glass system has long been of interest due to its potential to be converted into glass-ceramics containing spinel and cordierite phases. This study investigated the effect of adding varying amounts of cerium oxide (1-5% by weight) on the structure of the MgO-Al₂O₃-SiO₂ glass system. After mixing the raw materials, the samples were melted at 1600°C, and the density of the glass samples was measured using the Archimedes method. FTIR analyses, covering both far and mid-infrared ranges, as well as Raman spectroscopy, were conducted on the glass samples. To improve detection accuracy, the obtained spectra were deconvoluted. The results showed that the addition of cerium oxide increased the density from 2.53 g/cm³ to 2.69 g/cm³. Furthermore, the data indicated that cerium oxide in concentrations below 5% acts as a modifier. At lower concentrations, cerium predominantly exists in the Ce³⁺ state, increasing the number of non-bridging oxygens (NBOs), while at higher concentrations, Ce³⁺ is mostly converted to Ce⁴⁺, which in turn reduces the NBO concentration.
