Quantitative Analysis and Prediction of Elastic Properties of Tungstate-Tellurite Glasses Doped with Bi2O3

In this work, the elastic properties of two tellurite glass series 80TeO(2)-(20-x)WO3-xBi(2)O(3) (80TeWBi) and 70TeO(2)-(30-x)WO3-xBi(2)O(3) (70TeWBi) (where x = 0 mol.%, 5 mol.%, and 10 mol.%) were quantitatively analyzed and predicted. Many structural and compositional parameters, including the density of network bonds, mean cross-link density, average bond-stretching force constant, total packing density, and dissociation energy per unit volume, were calculated using bond compression (BC), ring deformation (RD), and Makishima-Mackenzie (M-M) models. These parameters were correlated with experimental elastic properties to explore the structural role of WO3 and Bi2O3 in the tellurite network. It was found that WO3 enters the tellurite network of Bi2O3-free 80TeO(2)-20WO(3) and 70TeO(2)-30WO(3) glasses as a network former. This stiffened the structure through the formation of WO4 tetrahedral units, WO6 octahedral units, and Te-O-W linkages. As a result, the theoretical bulk modules (K-bc) increased from 73.23 GPa to 83.90 GPa whereas the theoretical Poisson's ratio decreased from 0.235 to 0.225 with increasing WO3 mol.%. Meanwhile, Bi2O3 enters the network of TeO2-WO3-Bi2O3 glasses as a network modifier. This weakens the glass structure and results in the transformation of some TeO4 trigonal bipyramids into TeO3 trigonal pyramids by breaking the Te-O-W linkages and creating non-bridging oxygen atoms. Excellent agreement was achieved between the theoretical and experimental values of elastic moduli and Poisson's ratio.