The role of Nb2O5 on structural, mechanical, and gamma-ray shielding characteristics of lithium molybdenum borate glasses

Abstract

A series of glasses with the formula 64B2O3–16MoO3- (20-x) Li2O- xNb2O5 where x = 0 to 12, were synthesized. Utilizing XRD profiles, the amorphous state of the investigated glasses has been established. With an increase in Nb2O5 it is found that the gradual replacement of Li2O by Nb2O5 increases the density from 2.43 to 3.09 g/cm3 and the molar volume of the studied glasses decreases from 30.27 × 10−6 m3 mol−1 to 24.91 × 10−6 m3 mol−1. The addition of Nb2O5 increases the number of bridge oxygens and alters the coordination number of the glasses by forming BO4 structural units, according to the FTIR results. As the Nb2O5 increased ultrasonic velocities VL&VT also increased. VL increased from 4780 to 5150, and VT increased from 2295 to 2715 m/s. Ultrasonic velocity and elastic moduli increase as a result of structural changes brought on by an increase in BO4 at the expense of BO3. It is noted that the theoretically predicted elastic moduli utilizing Makishima-Mackenzie models (MMM) and the experimental elastic moduli indicate a very good agreement. The features of gamma-ray shielding were evaluated using the Phy-X/PSD program. It has been noted that the greatest mass & linear attenuation coefficient (MAC) & (LAC) occurred at 0.02 MeV. With an increase in energy, the half- and tenth-value layers HVL and TVL increased, while decreasing with an increase in Nb2O5. These observations suggest that the synthesized glasses are better candidates for gamma radiation shielding.