Hazardous-free alternatives for radiation shielding in medical diagnostics: BaO-doped TeO2-ZnO-CaO-B2O3 glass system

In this research work, a safe and hazard-free alternative to lead was investigated through the BaO-doped TeO₂-ZnO-CaO-B₂O₃ glass system, with BaO ranging from 5 to 30 mol%. The lead-free BaO-doped TeZnCaB glass systems have been synthesized by the melt-quenching method. X-ray diffraction (XRD) analysis confirmed the glassy structure of the BaO-based samples. The density of the developed glass samples was increased by doping the BaO concentration, ranging from 4.292 to 4.725 g/cm³. The structural features and vibrational modes of the BaO-based glass system were analyzed by FTIR (Fourier-transform infrared spectroscopy) and Raman spectroscopy, which revealed the existence of TeO₄, TeO₃, BO₄ and BO₃ structural units within the glass system. UV-visible characterization revealed that the optical energy band gaps were dropped with the BaO content, while the refractive index was enhanced. X-ray attenuation characterization was carried out to determine the shielding performance of the lead-free BaO-doped TeZnCaB glass system. It was observed that the LAC (linear attenuation coefficient) increased from 13.01645 to 16.23911 cm^-1 at 100 kVp with the addition of BaO concentration in the TeZnCaB glass samples. Moreover, increasing the BaO content in the developed glass samples resulted in a reduction in the MFP (mean free path), indicating improved radiation shielding efficiency. The glass samples with higher BaO contents demonstrated the best attenuation performance (shielding efficiency ~ 99%) and the Ba30 sample (i.e. the sample doped with 30 mol% BaO) exhibited the highest LET (lead equivalent thickness) of 2.627 mm. These glass samples could serve as a hazardous-free alternative, making them an effective and environmentally friendly radiation shielding choice for medical diagnostics applications.