Absorption Spectra of Neodymium Doped Tellurite Glass

摘要

Modifying the optical and structural properties of tellurite glasses by controlling rare earth doping is an important issue. Neodymium doped magnesium-tellurite glasses of composition TeO_2-MgO-Na_2O with concentration from 0.5 to 2.5 mol% were synthesized by conventional melt-quenching technique. The amorphous natures of the glass were confirmed from x-ray diffraction (XRD) pattern. The absorption spectra (exhibits five bands) were recorded to determine the optical energy gap and Urbach energy. The values of the optical band gap are found to lie between 3.04-3.20 eV, while the Urbach energy values varies are between 0.21-0.12 eV. The optical energy gap for indirect forbidden transition has increased whereas the values of Urbach energy have decreased with the increasing of Nd_2O_3 content. The structural and optical properties were found to be strongly affected by the varying concentration of Nd~(3+) ions.