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

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 Ti2p3/2 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.