Abstract
This study investigates the structural, mechanical, and radiation protection behavior of sodium phosphate glasses modified with 30 mol% Nb₂O₅ and varying MnO concentrations (0–7.5 mol%). Seven glass samples (S1–S7) were synthesized via the melt-quenching technique and characterized using FTIR, XRD, Vickers hardness testing, and MCNP simulations combined with XCOM theoretical calculations. FTIR analysis revealed that Nb₂O₅ primarily adopts octahedral coordination (NbO₆), acting as a network modifier, while MnO exhibits dual roles: Mn²⁺/Mn³⁺ ions modify the phosphate network at lower concentrations and participate in structural unit formation at higher concentrations. XRD confirmed the amorphous nature of all glasses. Mechanical testing demonstrated enhanced Vickers hardness (749–1800 MPa) with increasing MnO content, attributed to improved network rigidity. Radiation shielding evaluations highlighted superior gamma-ray attenuation for the S7 sample (7.5 mol% MnO), exhibiting the highest mass attenuation. coefficient (µ/ρ), lowest half-value layer (0.019–9.421 cm), and optimal radiation protection efficiency (100% at 30–100 keV). Neutron attenuation analysis revealed S7’s macroscopic removal cross-section (Σ(r) = 0.0956 cm⁻¹) outperformed conventional materials like concrete. The glasses demonstrated good stopping power and predicted range for protons and alpha particles with denser compositions (S7) showing enhanced charged particle attenuation. These findings position Nb₂O₅-MnO co-doped sodium phosphate glasses, particularly S7, as promising candidates for radiation shielding in medical, nuclear, and aerospace applications, combining mechanical durability with multi-radiation protection capabilities.