Effect of Ho³⁺ concentration on the luminescent and thermal stability of tellurite glasses

It is well known that optical properties of soft glasses can be improved by modifying the glass matrix or the lanthanides ions concentration. However, in the case of soft glasses doped with Ho³⁺ ions the information is limited to a few manuscripts that deals mainly with optical properties, neglecting the effect that could have in thermal properties. The present work shows the fabrication and characterization of Ho³⁺ doped tellurite glass samples ((78-x)TeO₂ - 10Nb₂O₅ - 10TiO₂ - 2Al₂O₃ - xHo₂O₃, where x = 0, 0.5, 1, 2 and 3 mol.%), prepared by melting and quenching technique. Differential scanning calorimetry were measured. In order to observe the characteristic energy levels of Ho³⁺ ions, UV-Visible absorption spectra and luminescence spectra under 488 nm excitation were recorded. The results showed that the incorporation of Ho³⁺ has a positive influence on thermal and luminescent properties as the Ho³⁺ concentration increases up 0 to 2 mol.%.