Elastic properties of TeO2-B2O3—ZnO-Gd2O3 glasses using non-destructive ultrasonic technique

The addition of Gd2O3 causes the glass system to be highly ionic resulting in increasing rigidity and the tendency of devitrification. Gd2O3 affects the strength governing the elastic properties of the glass. The elastic moduli of the prepared glasses are expected to increase with the addition of the Gd2O3 due to increasing net molecular weight of prepared glass resulting in strong connectivity and more compactness of the glass network. The objective of this present work is to study the elastic properties of TeO2-B2O3-ZnO doped Gd2O3 using a non-destructive ultrasonic technique. A series of {[(TeO2)0.7(B2O3)0.3]0.7(ZnO)0.3}1-x(Gd2O3)x glasses with x = 0.01, 0.02, 0.03, 0.04 and 0.05 mol were prepared by conventional melt-quenching method. Both longitudinal and shear ultrasonic velocities were measured using a pulse-echo method at a frequency of 5 MHz at room temperature. The elastic moduli (longitudinal modulus, shear modulus, Young’s modulus and Bulk modulus), Poisson’s ratio, Debye temperature, micro-hardness and softening temperature have also been quantified. The experimental results show that the elastic properties depend on the composition of the glass systems and the role of Gd2O3inside the glass network

Structural and optical properties of Tm2O3-doped zinc borotellurite glass system

Thulium doped zinc borotellurite glasses with composition {[(TeO2)0.7(B2O3)0.3]0.7[ZnO]0.3}1-x{Tm2O3}x were synthesized using melt-quenching technique. The values of x varied from 0.01 to 0.05 mol. The density and molar volume of the glass samples were found to increase with increased concentration of thulium oxide. FTIR analysis showed the existence of TeO4, BO3 and BO4 structural units in the glass network as well as the formation of bridging oxygens. XRD patterns confirmed the amorphous nature of the glass and were supported by the absence of sharp edges in the absorption spectra. All the optical data was found to vary with the concentration of Tm2O3. The direct and indirect optical band gap was in the range of 4.19 to 4.38 eV and 3.62 to 3.79 eV respectively. The trend for refractive index, molar refraction and molar polarizability was in opposite trend to the optical band gap and Urbach energy due to the variation of non-bridging oxygens (NBOs), increment of cross-link density, and also the existence of free electrons in the glass system