Abstract
Alkali boro-bismuthate glasses modified with MoO3 were explored using DTA. The activation energies for glass transition (E-g) and crystallization (E-p) were evaluated using the heating rate dependence of the glass transition temperature (T-g) and the peak temperature of crystallization (T-p), respectively. The study indicated a decrease in T-g, T-p, E-g, and E-p as a function of the MoO3 and Bi2O3 contents. This decrease is ascribed to changes in the alkali borate network. XRD was used to confirm the results of this study. The XRD analysis revealed the existence of crystalline phases such as Na2B4O7, Bi2MO6, and B1.5Mo0.25O3 in the amorphous alkali borate network. The kinetic exponents n and m that determine the crystallization reaction mechanism in the glasses were obtained using the experimental values of the crystallized volume fraction (chi). With the increase in x content, the n values decrease, which may be ascribed to the transformation from the three-dimensional network to the one-dimensional network, which decreases E-p values and crosslink density.