Thermally stimulated crystallization of (20-x)LiO{sub 2}-80TeO{sub 2}-xWO{sub 3} glass system

Tellurite glasses of the (20-x)LiO{sub 2}-80TeO{sub 2}-xWO{sub 3} system were synthesized (x=0, 5, and 10) and annealed at different temperatures, and the crystallization kinetics was studied using XRD, FTIR spectroscopy, and DSC techniques. XRD data evidenced the amorphous state of as-quenched samples, while thermally treated samples showed the growth of crystalline phases. FTIR spectroscopy was used to observe the evolution of the vibrational mode assigned to the TeO{sub 2} phases. The presence of {gamma}-TeO{sub 2}, {alpha}-TeO{sub 2}, and {alpha}-Li{sub 2}Te{sub 2}O{sub 5} crystalline phases was observed for the sample TL, x=0, while only the first and second phases were observed for TLW5 and TLW10 samples, x=5 and 10, respectively, suggesting that WO{sub 3} enters the structure preferentially as glass former, inhibiting the growth of the phase {alpha}-Li{sub 2}Te{sub 2}O{sub 5}. -- Graphical abstract: Typical DSC thermogram for TLW glasses for different heating rates with insert graphic showing as the Tg is evaluated. Display Omitted Highlights: {yields} The crystallization kinetics was studied using XRD, FTIR spectroscopy, and DSC techniques. {yields} The glass transition and maximum crystallization temperatures increase when the WO{sub 3} content in the glass composition was increased. {yields} The observed asymmetry of crystallization peaks suggests an overlapping of distinct crystallization phases ({alpha}- and {gamma}-TeO{sub 2}). {yields} The WO{sub 3} enters the structure as glass former and does not participate in the crystallization of glass.