Gamma ray shielding properties at 129·5 MBq and structural investigations of the Bi₂O₃–B₂O₃–K₂O–Li₂O–V₂O₅ glass system

Glass samples of the composition xBi₂O₃–(0·65–x)B₂O₃–0·15K₂O–0·15Li₂O–0·05V₂O₅ where 0≤x≤17 (mol%) have been prepared by the melt quenching technique and characterized by x-ray diffraction, Fourier transform infrared, Raman and UV-visible studies. Gamma ray shielding parameters have been measured at low absorption doses (129·5 MBq). The mass attenuation coefficients have been obtained experimentally and theoretically using NIST XCOM software at photon energies of 662, 1173 and 1332 keV. Good agreement has been observed between experimental and theoretical values of mass attenuation coefficients. These coefficients are further used to calculate half value layer parameter, mean free path and effective atomic number. The mass attenuation coefficients and half value layer parameters of the glass system have also been compared with nuclear reactor shield 'barite concrete'. Our bismuth containing samples exhibit better values than barite concrete at the same photon energies. Conversion of [BO₃] to [BO₄] units along with [VO₄] and [VO₅] structural units have been observed by FTIR spectroscopic techniques. UV-visible studies have been employed to calculate the optical band gap using Tauc's plots. It has been observed that the optical band gap increases with an increase in the content of Bi₂O₃ which is an indication of an increase in bridging oxygens. Optical properties including optical basicity, molar refraction, refractive index and optical electronegativity have been calculated and explained on the basis of structural changes occurring in the glass system.