Ultrasonic velocities, elastic modulus and hardness of ternary Sb-V2O5-TeO2 glasses

Quantitative analysis was done to achieve more insight on the mechanical and structural properties of xSb-(60-x)V2O5-40TeO2 (0 ≤ x ≤ 15 in mol%) glasses, prepared by melt quenching. Both room temperature longitudinal and shear ultrasonic velocities were measured by using pulse-echo method at frequency of 5 MHz. Using the ultrasonic velocities, longitudinal, shear, Young's and bulk elastic moduli, Poisson's ratio and Debye temperature were calculated and interpreted upon the number of bonds per unit volume nb, oxygen ion packing density OPD and mean atomic volume V̅. Results show anomalies with addition of Sb and show a behavior change at x = 12, confirming the changes in the rigidity and the content of non-bridging oxygens (NBOs). The obtained elastic moduli and Poisson's ratio confirm the previously reported trends of Makishima-Makenzie's theory with a relatively large deviations in amounts (up to 27%). These glasses were studied with respect to their Vicker's microhardness. The microhardness increases with Sb content and shows its maximum at x = 12 like elastic properties. A behavior change at x = 12 mol% in all recent data and also in previously reported optical band gap, oxygen molar volume and thermal stability implies to a drastic structural change with increasing Sb, associated to NBOs. Briefly, coincidence between the mechanical, structural, optical, and thermal data, suggests the glass with x = 12 as promising material in optical applications such as optical fibers because of its resistance against thermal and mechanical shocks.