Crystallization kinetics of the tungsten-tellurite glasses
JOURNAL OF NON-CRYSTALLINE SOLIDS, vol.357, no.1, pp.88-95, 2011 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 357 Issue: 1
- Publication Date: 2011
- Doi Number: 10.1016/j.jnoncrysol.2010.09.012
- Journal Name: JOURNAL OF NON-CRYSTALLINE SOLIDS
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Page Numbers: pp.88-95
- Yıldız Technical University Affiliated: No
Abstract
The crystallization kinetics of the (1 - x)TeO(2)-xWO(3) (where x=0.10, 0.15, and 0.20, in molar ratio) glass system was studied by non-isothermal methods using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. DSC measurements were performed at different heating rates to study crystallization kinetics of the first crystallization reactions of the glasses. XRD analysis of tungsten-tellurite glasses heat-treated above the first crystallization temperatures revealed that the first crystallization peaks attributed to the alpha-TeO(2) and gamma-TeO(2) crystalline phases for 0.90TeO(2)-0.10WO(3) and 0.85TeO(2)-0.15WO(3) samples and alpha-TeO(2) and WO(3) crystalline phases for the 0.80TeO(2)-0.20WO(3) sample. Avrami constants. n, calculated from Ozawa equation, were found between 1.14 and 1.44. The activation energies, E(A), for the first crystallization reactions were determined by using the modified Kissinger equation as 379 kJ/mol, 288.1 kJ/mol and 228.8 kJ/mol, for 0.90TeO(2)-0.10WO(3), 0.85TeO(2)-0.15WO(3) and 0.80TeO(2)-0.20WO(3) glasses, respectively. (C) 2010 Elsevier B.V. All rights reserved.