Experimental and computational modeling of Yb-doped phosphate glass: an ultrasonic and structural perspective

Yb2O3-doped aluminum–lead alkali phosphate glasses with the nominal composition 47P2O5–23Na2O–(24 − x)PbO–6Al2O3–xYb2O3 (x = 0.0, 0.1, 0.5, 1.0, and 3.0 mol%) were fabricated by melt-quenching and investigated using FTIR spectroscopy, ultrasonic pulse-echo measurements, and radiation-shielding calculations. The density slightly decreased from 4235 to 4182 kg·m− 3, while the molar volume increased from 33.21 × 10− 6 to 34.86 × 10− 6 m3·mol− 1 as x increased from 0.0 to 3.0 mol%. The ultrasonic velocities increased with Yb2O3 addition, where the longitudinal velocity rose from 3567 to 3663 m·s− 1 and the shear velocity increased from 2021 to 2089 m·s− 1, indicating a composition-dependent enhancement in elastic response. The Debye temperature increased from 296 to 302 K at the highest Yb2O3 content (3.0 mol%), supporting the observed stiffening trend. FTIR analysis, including band deconvolution, suggests that the phosphate network rearranges upon Yb addition and that modifier-related linkages form. This is in line with the changes in measured ultrasonic parameters that were reported to be caused by changes in composition. Radiation-shielding descriptors tested between 15 keV and 15 MeV show that the glasses we made have a lower half-value layer (HVL) than standard concrete and commercial RS-360 shielding glass. This shows that they could be good materials for shielding gamma rays in a small space.