Structural, thermal and photoluminescent properties of Eu2O3-Li2O-TeO⁠2 glasses

Lithium tellurite and lithium europium tellurite glasses containing 1-5 mol% Eu2O3 were prepared by melt quenching and their short-range structure, thermal and photoluminescent properties were studied by X-ray diffraction, density measurement, Differential Scanning Calorimetry (DSC), Raman and photoluminescence studies. DSC analysis found that the glass transition temperature correlates linearly with the average single bond enthalpy of the glass network and that increase in Li2O concentration from 20 to 25 mol% enhances the crystallization tendency while Eu2O3 addition enhances the glass thermal stability against devitrification. The addition of both Li+ and Eu3+ produces the structural transformation: TeO4 →TeO3. The photoluminescence studies show that Eu3+ ions in Li2O-TeO2 glasses produce sharp and intense luminescent peaks in the red-orange wavelength region of the electromagnetic spectrum and the luminescence intensity enhances with increase in Eu2O3 concentration from 1 to 5 mol%.