Tuning radiation attenuation performance of W-substituted nano-BiNb₁₋ₓWₓO₄ ceramics: A Monte Carlo simulation approach

High density ceramics are crucial to next-generation radiation shields because the attenuation of γ- and X-rays scales almost linearly with the atomic number and mass density of the barrier medium. Bismuth and tungsten-based oxides, in particular, can match or surpass lead in stopping power while avoiding its toxicity. This work presents the synthesis of the BiNb₁-ₓWₓO₄ solid solution with x = 0, 0.25, 0.50, 0.75, 1.00 mol% by solid state reaction route. The X-ray diffraction (XRD) shows that the orthorhombic α-BiNbO₄ structure changes into the orthorhombic Aurivillius structure when the x value increases. At x=0.5 mol%, show peak splitting and systematic 2θ shifts, which suggest that a full solid solution has formed instead of only physical mixtures. Fourier-transform infrared (FTIR) spectra show the typical Nb-O and W-O stretching doublets. The average size of the particles in all of the compositions was less than 100 nm. Ion-transport simulations reinforce this promise. The Stopping and Range of Ions in Matter (SRIM) code shows that as the tungsten content increases, the electronic stopping cross-section (SCS) and projected range (PR) of proton energy decrease within an energy range from a few eV to 100 MeV. Damage profiling shows that 5 MeV protons are able to penetrate to a depth of 0.78 mm into Bi₂W₂O₉ of 3 mm of the total thickness. These results show that high W content BiNb₁₋ₓWₓO₄ is highly effective at ion quenching, which supports its application as a high performance, environmentally friendly material for shielding for radiation and particle beams. The Monte Carlo simulation was employed to evaluate the radiation shielding efficacy of BiNb₁₋ₓWₓO₄ solid solution over the energy range of 0.015 to 15 MeV. Replacing the Nb ions with W ions significantly enhances the shielding performance of the materials. The linear attenuation coefficient for the was increased by 46.81%, 23.06%, and 16.64% at 0.122 MeV, 0.662 MeV, and 1.332 MeV, respectively, when x varied from 0 to 1. As W ions substitute the Nb ions, the half-value thickness and the equivalent thickness were decreased.