Influence of Pr3+ions on the structural properties of Er3+-doped tellurite-tungsten glasses

An understanding of the optical, thermal and structural properties of tellurite glasses is necessary for the development of new technological applications. Previous works have already been published studying the properties mentioned above, however, the mechanism of modification of the glassy structure due to the addition of rare earth ions is still an open topic in materials science. In this paper, we report the mechanisms of structural modification of the Er3+ and Pr3+-doped glass tellurite-tungsten system through a systematic study. TeO2-ZnO-WO3-GeO2 glasses codoped with Er2O3 and varying the content of Pr2O3, was prepared by the conventional melt-quenching technique and studies of its structural, thermal and spectroscopic properties were carried out. The direct and indirect bandgap energies and the Urbach energy evidence an increase in the structural disorder of the glassy matrix due to the deformation of the Te-O linkages by the insertion of Pr3+ ions in the sample can be suggested. Raman spectroscopy results showed an increase in TeO3+1 and TeO3 compared to TeO4 when the Pr2O3 doping was increased, modifying the structural coordination in TeO2, generating non-bridging oxygens. Raman spectroscopy in low-frequencies shows the Boson peak changed with the increase in the concentration of Pr3+. Furthermore, was obtained that transverse modes predominate in low Raman frequencies. This work suggests that the presence of Pr3+ ions influences the optical and thermal properties, in addition to altering the local glassy structure, generating a change in the coordination of network formers such as TeO2.