The role of CeO2 doping in soda–lime silicate glass: structural and thermal properties

This study investigates the structural and thermal properties of cerium-doped soda–lime glasses. A series of glasses with varying CeO₂ concentrations (0.6–15 wt.%) were synthesized via the melt-quenching technique in alumina crucibles, yielding homogeneous, amorphous materials characterized by SEM, EDX, XRD, FTIR, Raman spectroscopy, and differential thermal analysis (DTA). Potentiometric titration confirmed the presence of tetravalent cerium (Ce⁴⁺) and trivalent cerium (Ce³⁺) as the dominant oxidation state. Structural studies revealed Ce-induced silicate network depolymerization, evidenced by shifts in Qⁿ unit distribution (Q⁴ → Q³/Q²) in FTIR/Raman spectra and increasing O:Si ratios. Despite this depolymerization, the effective cationic field strength (ECFS) rose with both Ce³⁺ and Ce⁴⁺ incorporation, driven by their high bond strengths, counteracting network fragmentation. Consequently, the glass transition temperature (T_g) increased monotonically with Ce⁴⁺ content (611 °C to 634 °C), while thermal stability (S) decreased due to enhanced crystallization tendencies. Aluminum oxide diffusion from crucibles (1–3 at%) further complicated compositional trends, influencing ECFS and crystallization kinetics. Optical basicity (Λ≈0.58) remained invariant, underscoring its insensitivity to localized Ce⁴⁺ structural changes. These findings highlight valuable insights into the structural role of cerium in soda–lime glasses and its potential for optimizing glass properties for advanced technological applications.