Thermal Property of BaO-TiO2-GeO2 Glass and the Crystallization Behavior
Correlation between surface crystallization behavior of BaO-TiO2-GeO2 (BTG) glass and the thermal stability parameter measured by Differential Thermal Analysis (DTA) was examined. We have proposed normalized thermal stability ΔTnorm of the BTG glass using crystallization temperature (Tx), glass transition temperature (Tg), and melting temperature (Tm). It was found that surface crystallization occurred in the BTG glass possessing ΔTnorm (= (Tx-Tg)/Tm) value larger than 0.08. Compared ΔTnorm value of bulk state with that of powdered state, it has been revealed that Ba2TiGe2O8 was precipitated independently of thermal stabilities whereas BaTiGe3O9 or BaGe4O9 was precipitated in precursor glasses possessing high surface stability.
Shinobu Fujihara and Tadashi Takenaka
Y. Yamazaki et al., "Thermal Property of BaO-TiO2-GeO2 Glass and the Crystallization Behavior", Key Engineering Materials, Vol. 445, pp. 179-182, 2010