et al.. Synthesis, thermal, structural and linear optical properties of new glasses within the TeO2-TiO2-WO3 system. Abstract.The glass-forming domain and physical properties, namely, the density, thermal, structural and linear optical properties of new glasses within the TeO2-TiO2-WO3 system have been investigated. By means of micro-Raman spectroscopy, the structure of these glasses was examined based on a full-scale spectral decomposition. The optical transmission and refractive index dispersion were measured by UV-Vis-NIR spectroscopy and spectroscopic ellipsometry respectively. Consistent correlations were established between the structural and linear optical properties. Only minor structural modifications of the original TeO2-rich network are taking place upon adding TiO2 or WO3, suggesting the absence of Te-O-Te bond network depolymerization. Our results also suggest that, upon increasing TiO2 content, a phase separation occurs between amorphous TeO2-rich and amorphous TiO2-rich regions. We also argue that the structural trends upon adding WO3 evolve from uniformly dispersed WO6 octahedra (at low WO3 content) to amorphous WO3-like regions (at higher WO3 content) before the crystallization of γ-WO3 at 30 mol.% of WO3. The compositional dependence of the refractive index and several optical constants (Urbach EU and dispersion Ed energies, oxide ion polarizabilities) is highlighted. These glasses collectively exhibit high refractive indices in the order of ~2.2. Graphical abstract. Highlights. New glass-forming domain within the TeO 2 -TiO 2 -WO 3 system was determined. Relevant correlations between the structural and optical properties are established. Structural effects of TiO 2 and WO 3 are revealed and discussed in detail. The investigated glasses exhibit high refractive indices in the order of ~2.2. Keywords.Tellurite glasses; glass structure; Raman spectroscopy; linear optical properties.is found that upon adding WO 3 from 5 to 25 mol.%, α O2-slightly increases from ~1.6 to ~1.8 Å 3 while remaining practically constant with addition of TiO 2 . This slight increase of α O2-values indicates that the overall glass network becomes slightly more "polarized", and thus a little more ionic in nature. Conclusions.A new TeO 2 -based glass-forming domain has been explored and investigated within the ternary TeO 2 -TiO 2 -WO 3 system. Density, thermal, structural and linear optical properties have been measured and analyzed as a function of TiO 2 and WO 3 contents.The structural properties of TTxWy glasses were examined using micro-Raman spectroscopy to highlight the structural roles and effects of adding TiO 2 and WO 3 on the short-to mediumrange structure. We report the following structural trends:  Globally, only minor structural modifications are taking place upon adding TiO 2 or WO 3 , (i) indicating that TTxWy glasses collectively share common features of the pure TeO 2 glass network and (ii) suggesting the absence of Te-O-Te bond network depolymerization (induced transformation of TeO 4 into TeO 3 units)...

The glass-forming domain, density, thermal, structural and optical properties of new glasses within the TeO2-NbO2.5-WO3 system have been investigated. By means of Raman spectroscopy, a thorough structural analysis of these glasses has been undertaken on the basis of a full-scale spectral decomposition process. The optical transmission window, refractive index dispersion and third-order nonlinear susceptibilities χ (3) were measured by UV-Vis-NIR spectroscopy, spectroscopic ellipsometry and Z-scan method respectively. Consistent correlations are successfully established between the measured structural, linear and nonlinear optical properties. In general, the structural features of the glass network are found to evolve mildly upon adding NbO2.5 or WO3. Nonetheless, a weak structural depolymerization of the Te-O-Te bond network as a result of adding NbO2.5 is evidenced and discussed in detail.