Novel PdO-modified borate glasses with improved radiation shielding and mechanical features

Novel PdO-borate glasses with low PdO concentrations were synthesised via melt-quenching for the first time. The prepared glass samples are amorphous, as revealed by XRD, and their densities increase from 4.457 to 4.729 g cm^-3 with increasing PdO content. Increasing the PdO content at the expense of B₂O₃ yields higher experimental elastic moduli determined by the ultrasonic pulse-echo method, with Young's modulus increasing from 51.9 to 70.1 GPa and the bulk modulus from 34.3 to 56.1 GPa. These values exceed the elastic moduli computed via the Makishima-Mackenzie model. The radiation shielding parameters calculated with Phy-X/PSD, compared with NIST-XCOM, show deviations of ≤1.36% and improved attenuation at low and moderate energies. At 0.015 MeV, the linear attenuation coefficient increased from 128.4 to 140.5 cm^-1. At 0.6 MeV, the half-value layer decreased from 1.925 to 1.817 cm. The glass sample having 2 mol% of PdO exhibits enhanced mechanical strength and γ-ray shielding, making it a practical, lead-free choice for medical and nuclear radiation protection applications.