Chemical compositions and crystallization behavior of BaO-TiO2-GeO2 Glass

We prepared glasses in 30BaO-(15+x)TiO2-(55-x)GeO2 composition (x=0, 10, 20, 35) and examined their crystallization behavior. Relation of crystallizing-phase to optical transparency in the resulting crystallized sample was also considered. Although the glass samples with x=0-20, which precipitate fresnoite-type Ba2TiGe2O8 as main phase, lost transparency after crystallization, the glass with x=30, which precipitates BaTi4O9 phase, kept good transparency. Dependence of transparency on the x is also discussed.