Network structure of tellurite phosphate glasses: Optical absorption and infrared spectra

A series of binary tellurite-phosphate glasses in the form [TeO2]0.81[P2O5]0.19 doped with different rare-earth oxides were prepared. The rare-earth oxides were: La2O3, CeO2, Pr2O3, Nd2O3, Sm2O3, and Yb2O3. The optical absorption coefficient and infrared spectra were measured in the ranges 200–900 nm and 200–1000 cm−1, respectively. It is found that the fundamental absorption edge depends upon the kind of the dopant cation. The infrared spectra of these doped glasses indicate that the rare-earth oxides are connected to the chains of TeO4.