Effects of Nb2O5 Replacement by Er2O3 on elastic and structural properties of 75TeO2-(10 − x)Nb2O5-15ZnO-(x)Er2O3 glass

► Elastic properties of 75TeO2-(10-x)Nb2O5-15ZnO-(x)Er2O3, x = 0.0-2.5 mol% glasses were studied by ultrasound. ► Shear velocity and shear and Young's moduli decreased at x = 0.5 mol% before maintaining almost constant value of both longitudinal and shear velocity and their related elastic moduli between x = 0.5-2.0 mol%. ► A large increase in ultrasonic velocity for both modes and their related elastic moduli were observed at x = 2.5 mol%. ► FTIR analysis indicates increase in bridging oxygen improves the glass network rigidity.