The structure, optical basicity, ligand field strength and shielding parameters of alkali/alkaline borate glasses doped with V2O5

In this work, we study the structural, optical and radiation shielding properties of Na2O–CaO-borate glass doped with different amounts of V2O5. A glass system with the composition (10.5CaO+ 16.5Na2O+ (73-x)B2O3+ xV2O5; where x = 0, 2.5, 5 and 10.5 mol%) was produced following the melt quenching technique. The molar volume and density of glasses both increase with the increase in V2O5:B2O3 ratios. Moreover, the average ligand field strength reduced from 2.32 to 2.15 × 1016 cm2 with the increase in V2O5:B2O3 ratios, which correlates with the increased values of molar volume and interatomic separations. Furthermore, the optical basicity of the glass samples increased from 0.601 to 0.666 with increasing V2O5:B2O3 ratios. The optical absorption spectra are studied for further investigation of the optical features. To extract the absorption edge and the absorption bands, a deconvolution process was applied to the absorption spectra. The obtained bands from this deconvolution process confirmed the presence of vanadium in its oxidation states V3+, V4+ and V5+. Furthermore, more additions of V2O5 produced an obvious reduction in Eg values from 3.69 to 3.08 eV along with a redshift in the fundamental absorption edges. These results were attributed to the further creation of nonbridging oxygens within the glass matrix. Furthermore, the addition of V2O5 rather than B2O3 enhances the radiation shielding parameters. Accordingly, the CaNaBV10.5 glass sample is the best attenuator among the fabricated CaO–Na2O–B2O3–V2O5 glasses due to the highest mass attenuation coefficient and lowest half-value layer. Moreover, the half-value layer values of the present glasses were compared to some common materials in the radiation shielding field. From this comparison, we concluded that all glass samples are better than commercial glass windows and ordinary concrete.