Synthesis, thermal and structural properties of pure TeO2 glass and zinc-tellurite glasses

Features of electronic polarizability and approach to unique properties in tellurite glasses

“…Consequently, it is considered that ZnO‐TeO 2 glasses have the large optical basicity of ∧( n o ) ~ 0.95 and a weak dependence of ZnO/TeO 2 ratio on ∧( n o ). Tagiara confirmed from Raman spectra that the addition of ZnO in ZnO‐TeO 2 glasses causes the progressive conversion of TeO 4 tbp units to TeO 3+1 polyhedra with two terminal oxygens, and then to TeO 3 tp units with three terminal oxygens. Thorbahn and Zwanziger proposed from Zn‐extended X‐ray absorption fine structure (EXAFS) that ZnO acts mostly as a network modifier, breaking Te‐O‐Te linkages, for low ZnO compositions, and a network of ZnO 4 tetrahedra is formed at higher ZnO contents.…”

“…Here, some aspects on the structure and group optical basicity in tellurite glasses are reviewed shortly. The structure of pure TeO 2 itself is still subject to discussion . Gulenko et al proposed from classical molecular dynamics that TeO 2 glass consists of various TeO x structural units ( x = 3,4, and 5) with either bridging oxygen (BO) atoms or nonbridging oxygen (NBO) atoms and a large amount of NBO atoms plays an important role in forming the glass structure with an open network (large rings) and a weak connectivity.…”

“…Indeed, the glass transition temperature, which is regarded as a measure of the bond strength of glass network structure, in tellurite glasses lies almost in the range of 250‐400°C . Pure TeO 2 glass has a value of T g = 301°C . Tellurite glasses also show low temperature melting behavior because of weak bond strengths between TeO x polyhedral units.…”

“…TeO 2 is a conditional glass‐forming oxide, and the synthesis of pure TeO 2 glass requires an extremely rapid melt‐quenching technique . Tagiara et al managed recently to synthesize pure TeO 2 glass in bulk form by a newly developed technique, which involves rapid and repeated immersion of the bottom of the platinum crucible into water at room temperature. On the other hand, in multi‐component systems such as Na 2 O‐ZnO‐TeO 2 , thermally stable TeO 2 ‐based glasses, that is, tellurite glasses, are prepared easily using a conventional melt‐quenching method .…”

Optical and Thermal Properties of Some Tellurite Glasses

“…Recently, the absorption spectrum fitting method (ASF) and derivation of absorption spectrum fitting (DASF) methods have been introduced to obtain the band gap avoiding the film thickness measurement which commonly could not be measured precisely [13,14]. Also, tellurite glasses with high thermal and glass stabilities were suggested as potential materials to realize highly efficient fibers [15][16][17][18][19][20].…”