Abstract: The effects of rare earth, alkali and Al ions on the thermal, short-range structure, optical absorption and emission properties of barium tellurite and barium boro-tellurite glasses are studied. The glass transition temperature and density correlate with the average single bond energy of the glass network and the molecular mass of the constituents, respectively. Glasses containing Eu3+ shows strong red emission peaks at 613 nm and 595 nm. The emission spectra of Dy3+-doped glasses show two peaks due to 4F9/2 - 6H13/2 (578 nm) and 4F9/2 - 6H11/2 (668 nm) transitions. The downconversion spectra of Er3+-doped glasses (excited at 380 nm) have emission bands due to 2H11/2 - 4I15/2 (524 nm), 4S3/2 - 4I15/2 (545 nm), and 4F9/2 - 4I15/2 (657 nm) transitions. The addition of B2O3 in the tellurite network does not produce any significant modification in the emission intensity, but it enhances the thermal stability and optical transparency of glasses. The photoluminescence intensity shows strong quenching effects with an increase in Dy2O3 and Er2O3 concentrations from 1 to 7 mol%, however these effects were not found in Eu2O3 containing glasses, which on the contrary show a continuous enhancement in luminescence intensity with an increase in Eu2O3 concentration. Raman studies show that the addition of metal oxides produces short-range structural transformation: TeO4 ? TeO3 units in the tellurite glass network.

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