Characterization of Nd3+-doped tellurite glasses with low OH content

Abstract

This work presents the results of the investigation of structural and thermal properties of Nd3+-doped tellurite glasses with low OH content. The samples were characterized by XRD, FTIR, DTA, UV/VIS/NIR and Archimedes' method. Tellurite glasses of composition (100-x)(0.8TeO2 + 0.2WO3) + xNd2O3 (x = 0, 0.05, 0.5, 1, 2, and 4 mol%) were prepared in both ambient and oxygen atmospheres. All samples showed an increase of the values of Tg, Tx, and Tx-Tg with Nd2O3 addition. The reduction of OH content implies a slight decrease of Tg. The density and the molar volume of the glasses increased with Nd2O3. The intensity of the absorption bands associated with Te-O bonds of TeO4 units decreased compared with the bands associated with Te-O bonds of TeO3+1/3 units. This indicates that Nd2O3 favors the transformation of the TeO4 groups in TeO3 groups via TeO3+1, increasing the NBOs and contributing to the formation of strongly hydrogen-bonded OH groups. The samples made in O2 showed a reduction of 48% of free OH ions compared with the Amb ones.