ABSORPTION STUDIES OF ERBIUM DOPED SODIUM MAGNESIUM BORO-TELLURITE GLASS

Abstract

A series of erbium doped sodium magnesium boro-tellurite transparent glasses of composition (30-x) B₂O₃-45TeO₂-15MgO-10Na₂O-xEr₂O₃ (where x=1.0, 1.5 and 2.0 mol %) has been prepared by the conventional melt-quenching technique. X-Ray Diffraction (XRD) pattern confirms the amorphous nature of the prepared glasses. The physical and optical properties of glass samples are characterized in terms of density, molar volume and UV–VIS–NIR, respectively. The glass density increases as it is found to be in the range of 3.928 up to 3.982 (g/cm³) and and molar volume are found vary from 27.57 to 27.93 (cm³ mol^-1). The absorption spectra reveals eight absorption bands with transition from ⁴I_15/2 to ⁴F_5/2, ⁴F_7/2, ²H_11/2, ⁴S_3/2, ⁴F_9/2, ⁴I_9/2, ⁴I_11/2 and ⁴I_13/2. The optical energy band gap, and Urbach energy, are calculated from the observed absorption spectra which are found to be decreased in the range of 3.32 to 3.26 eV while the Urbach energy values increase between 0.18-0.21 eV respectively. The variations of and values are depending on the Er₂O₃ content in the host matrix. The optical properties of the prepared glasses with the change in Er₂O₃ content have been studied and compared with previous results.