Effect of WO₃ on the glass transition and crystallization kinetics of borotellurite glasses

Abstract

Tellurite glasses of the system xWO₃–75TeO₂–(25 − x)B₂O₃ (0 ≤ x ≤ 25 mol. %) were prepared and studied by differential thermal analysis to explore the effect of WO₃ on their glass transition and crystallization kinetics. The crystallization kinetics was studied under non-isothermal conditions using the formal theory of transformations for heterogeneous nucleation. The crystallization results were analyzed and both the activation energy of the crystallization process and the crystallization mechanism characterized. The phases into which the glass crystallizes were identified by X-ray diffraction. Diffractograms of the transformed material indicate the presence of microcrystallites of α-tellurite, Te_0.95W_0.05O_2.05, Te₂W and B₂O₃ in the amorphous matrix.

Keywords:

• tellurite glass
• crystallization kinetics
• differential thermal analysis