Study of the effect of doping CeO2 in TeO2-MoO-Bi2O3 ceramics on the phase composition, optical properties and shielding efficiency of gamma radiation

This paper presents data on the study of changes in the structural, optical, and gamma radiation shielding characteristics of TeO2-MoO-Bi2O3 ceramics doped with CeO2. Doping was carried out by adding CeO2 powder to the composition of ceramics during mixing in the following molar proportions of 0.05, 0.10, 0.15, 0.20, and 0.25 mol %. Using the method of X-ray phase analysis, the dynamics of phase transitions was established: Bi6Te2O13/Bi4MoO9 -> Bi4MoO9/CeTe2O6. It was found that an increase in the concentration of the dopant leads to a change in the content of the phases, followed by the equilibration of the Bi4MoO9 and CeTe2O6 phases at a dopant concentration of 0.20 and the dominance of the CeTe2O6 phase at a concentration of 0.25. During the determination of optical characteristics, it was found that doping leads to sharp change in the fundamental absorption edge and a decrease in the Eg value from 2.27 eV to 1.87 eV, as well as the appearance of two absorption bands with energies of 1.72 eV and 2.39 eV. During the determination of gamma radiation shielding characteristics, it was found that an increase in the concentration of CeO2 leads to an increase in gamma radiation shielding efficiency exceeding 50% for dopant concentrations above 0.15 M in the composition of ceramics.