Raman spectroscopic studies of quaternary tellurite glasses containing Nb2O5 and Ta2O5

Murugan, G.Senthil, Suzuki, T. and Ohishi, Y. (2005) Raman spectroscopic studies of quaternary tellurite glasses containing Nb₂O₅ and Ta₂O₅. Physics and Chemistry of Glasses, 46 (4), 359-364.

Record type: Article

Abstract

New quaternary glasses in the systems TeO₂–BaO–SrO–Nb₂O₅ and TeO₂–BaO–SrO–Ta₂O₅ are prepared, and are found to have improved thermal stabilities and refractive indices, making them suitable for photonics device applications. Systematic Raman spectroscopic studies of these glasses are undertaken to unravel the presence of various structural units, and the contributions made by them with varying modifier oxides contents have been quantified. A comparative study is made on the evolution of various structural units with the addition of modifier oxides in the two glass systems. The Raman bandwidths of these glasses are broader compared to conventional tellurite glasses. Both glass systems show an additional Raman band beyond 870 cm^-1 that is not present in other tellurite glass systems. The Nb–O related vibrational band near 870 cm^-1 is stronger than the band around 900 cm^-1 in the Ta₂O₅ containing glasses. The coordination geometry of tellurium atoms in the presence of Nb₂O₅ and Ta₂O₅ is discussed with the help of molecular modelling results.