Electronic polarizability, dielectric constants, and the capability of using (24-x)PbO–47P2O5–23Na2O–6Al2O3: x = 0.0, 0.5, 1.0, and 3.0 mol% MoO3 as γ-rays shielding materials were investigated. The linear refractive index of glasses changed from 2.059 to 2.514. The molar polarizability was directly proportional to molar refraction. The mass attenuation coefficients varied between 0.1850- 0.0401 and 0.1762- 0.0399 cm2/g for Mo0.0 and Mo3.0 glasses between 0.284 and 2.506 MeV. The replacement of PbO by MoO3 is found to decrease the attenuation ability of the tested samples. The maximum linear attenuation values for all samples occur at 0.284 MeV and equal to 0.684, 0.661, 0.626, and 0.546 cm−1 for Mo0.0, Mo0.5, Mo1.0, and Mo3.0 glasses, respectively, which suggested that the tested Mo0.0–Mo3.0 samples have better attenuating behavior at lower energies. The effective atomic number decreases in the order Mo0.0, Mo0.5, Mo1.0, and Mo3.0. Mo0.0 glass showed the highest effective atomic number among the tested glasses, which revealed that Mo0.0 has better attenuation features among the investigated glasses. The minimum effective atomic number was found at 1.33 MeV and equal to 12.45, 12.42, 12.39, and 12.26 for the Mo0.0, Mo0.5, Mo1.0, and Mo3.0 samples. The Phys-X software was applied to determine the half value thickness for the investigated glasses between 0.284 and 2.506 MeV. The usage of different percentage of PbO and MoO3 in the chosen glasses had been found to notably affect the half value thickness of the glasses. The half value thickness values are small at low energy and then increase with increasing the energy of the photon and reach the maximum values at 2.506 MeV. At 2.506 MeV, the half value thickness varied between 4.678 and 5.601 cm.
