Study on structure and properties of La2O3–TiO2–B2O3 system glass

High refractive index La2O3–TiO2–B2O3 (LTB) system glasses have been successfully prepared by traditional melt-quenching method. Based on XPS results, we acquire details regarding the Ti oxidation state, coordination environments of boron and titanium, and the ratio of bridging to non-bridging oxygens within the glass. The predominant structural units identified in the glass matrix include [BO4], [BO3] and [TiO5] polyhedra, alongside a fraction of [TiO4] and [TiO6] polyhedra. The incorporation of TiO2 results in a reduction of the [BO4] tetrahedral groups and an increase of bridging oxygens and non-bridging oxygens bonds with Ti within the glass structure. 20 % of Ti(Ⅳ) ions in the glass are reduced to Ti(Ⅲ) ions. The addition of TiO2 content leads to an increase in Vickers hardness and refractive index of the glass, with [TiO5] polyhedra notably enhancing the refractive index. However, the increase in TiO2 content correspondingly decreases glass transmittance due to the charge transfer between Ti4+ or Ti3+and O2−.