The Effect of Melting Temperature on Coloration of TiO₂–BaO–SiO₂ Glass

Abstract—TiO₂–BaO–SiO₂ glass have been prepared by melt quenching method. The enhancement of glass coloration was observed as melting temperature increase. UV-Vis-NIR spectrophotometer reveals the change of glass transmittance. And the Ti2p_3/2 and O1s XPS results shows that Ti ions exist in the Ti³⁺ and Ti⁴⁺ state in glass, Ti³⁺ proportion increased as melting temperature increasing, while more fourfold coordination [TiO₄] tetrahedron appeared as the substitute of sixfold coordination [TiO₆] octahedron. According to the analytic results, we demonstrate that the lack of free oxygen in glass at high melting temperature cause the decrease of the valence and coordination for Ti, and the strong absorption of Ti³⁺ and [TiO₄] enhances the coloration of glass.