Tailoring variations in the linear optical and radiation shielding parameters of PVA polymeric composite films doped with rare-earth elements

The present work aims to study the structure and physical properties of PVA doped with two rare-earth oxides (dysprosium (III) oxide and erbium (III) oxide). Pure and doped polyvinyl alcohol (PVA) samples with 10 wt% and 30 wt% Er+3 and Dy+3 nanoparticles (NPs) have been fabricated via the casting method. The optical and radiation shielding properties of these composites were studied. The UV–Vis absorbance spectra of the doped PVA samples were investigated to study and characterize the alteration of the bandgap structure due to optically induced electronic transitions. UV–Vis was measured using a Shimadzu UV-2450 spectrophotometer at a range of (190–900 nm). The direct band gap and indirect band gap for both films depend on doping materials as given in indirect values (4.36–5.16 eV) and direct value (5.23–5.64 eV). The radiation attenuation properties were investigated experimentally with gamma spectroscopy at an energy range of (81–2614 keV). These properties were in good agreement with results provided by the XCOM software. Using 0.662 MeV, the studied samples exhibited experimental half value layer (HVL), of 7.30287 cm, 3.14412 cm, 2.80605 cm, 2.76987 cm and 2.37733 for Pure PVA, PVA10Dy, PVA10Er, PVA30Dy and PVA30Er samples. Furthermore, the results show that the sample with 30 wt% Er+3 has the highest LAC and MAC values and the lowest MFP, HVL and TVL values, making it the best sample for blocking out gamma radiation.