Calcium Silicate Glass Ceramics Containing Chromium Sulfate: Structural, Optical, and Shielding Properties

New silicate glass–ceramics in the system x Cr 2 (SO 4 ) 3 -(45 − x )SiO 2 -55CaO, where x = 0, 3, 6, 9, and 12 mol.% have been prepared via the hydrothermal method. Combined optical, and FTIR spectral measurements together with radiation shielding parameters were correlated. X-ray diffraction patterns (XRD) for all the investigated glasses have revealed a polycrystalline nature. Absorption peaks in FTIR spectra were mainly assigned to be due to the vibration modes of SiO 4 , SO 4 , and CrO 4 different functional groups. The UV results indicated that, with the increasing content of Cr 2 (SO 4 ) 3 , there was a decrease in the optical energy gap, coupled with an increase in the refractive index. Molar refraction, transmission coefficient, molar polarizability, and optical dielectric constant were calculated and discussed. The density values of all the as-prepared samples were calculated and they do not show any significant change with an increase in Cr 2 (SO 4 ) 3 concentrations, while the molar volume was clearly increased from 22.24 to 34.85 cm 3 /mol. The obtained results have showed that molar volume and free volume increased with the introduction of Cr 2 (SO 4 ) 3 as a result of the SiO 4 , SO 4 , and CrO 4 units formation. In contrast, the decreasing behavior in the oxygen molar volume is considered to be due to the former role of Cr 2 (SO 4 ) 3 . A new development Phys-X/PSD computer program has been used to compute shielding parameters in the energy range of 0.015 to 15 MeV. The obtained results indicated that the physical and shielding characteristics of the tested glasses are enhanced by the insertion of Cr 2 (SO 4 ) 3 content, giving the material additional advantages for optical and shielding applications.