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This qualitative work focuses on a comparison between the roles of a lanthanide oxide CeO2 and a transition metal oxide Cu2O3 when introduced to sodium borate glass. Two glass samples have been prepared using the fast quenching method, where two types of glasses were obtained: (i) copper-free/cerium-rich sodium borate glass, and (ii) cerium-free/copper-rich sodium borate glass. XRD patterns indicated the amorphous nature of the prepared samples regardless of the dopant type, either CeO2 or Cu2O3. The optical characterization showed that the CeO2-doped and Cu2O3-doped samples have the same Urbach energy, resonance frequency, and damping factor. But differ in the values of the transmittance, reflectance, plasmon frequency, and the concentration of the free charge carriers. The acquired results may recommend CeO2-doped borate glasses as major components in the field of data transfer materials, such as those used in the manufacture of computer chips, whereas Cu2O3-doped borate glasses were proposed for applications involving) attenuation of the low energy light (UV–VIS–NIR). [ABSTRACT FROM AUTHOR]

This work aims to prepare modified glassy barriers of the composition (70 − x) mol% B2O3 + 20 mol% Na2O + 10 mol% BaO + x mol% La2O3 for use as radiation shielding materials. The cooling method has been considered for the sample's preparation process. The structural properties were investigated using density and Infrared Spectroscopy. The hardness of the prepared glasses was studied. The optical transmittance and absorbance of the prepared glasses was measured using optical spectra measurements. The prepared samples were exposed to a parallel beam of gamma rays emitted from different radioactive sources. Moreover, the shielding properties were evaluated experimentally and theoretically. The resulting value of the proposed programs is largely in line with the experimental values. The results prove that the studied glass has a largely shielding behavior for gamma rays by increasing lanthanum and vice versa for neutrons. In addition, it has been observed that the absorbance of glass samples and hardness values increase with increasing lanthanum content. [ABSTRACT FROM AUTHOR]

This study presents a new approach towards the production of sol-gel silica-coated Bi2O3/Gd2O3 cement additives towards the improvement of early mechanical performance and radiation attenuation. Two types of silica coatings, which varied in synthesis method and morphology, were used to coat Bi2O3/Gd2O3 structures and evaluated as a cement filler in Portland cement pastes. Isothermal calorimetry studies and early strength evaluations confirmed that both proposed coating types can overcome retarded cement hydration process, attributed to Bi2O3 presence, resulting in improved one day compressive strength by 300% and 251% (depending on coating method) when compared to paste containing pristine Bi2O3 and Gd2O3 particles. Moreover, depending on the type of chosen coating type, various rheological performances of cement pastes can be achieved. Thanks to the proposed combination of materials, both gamma-rays and slow neutron attenuation in cement pastes can be simultaneously improved. The introduction of silica coating resulted in an increment of the gamma-ray and neutron shielding thanks to the increased probability of radiation interaction. Along with the positive early age effects of the synthesized structures, the 28 day mechanical performance of cement pastes was not suppressed, and was found to be comparable to that of the control specimen. As an outcome, silica-coated structures can be successfully used in radiation-shielding cement-based composites, e.g. with demanding early age performances. [ABSTRACT FROM AUTHOR]

In this work, the multivalent transition metal oxide, Cu2O3, has been added in different content to the primary constituents of the Ca/Na lead Arseborate oxide glass. These required glasses were created using the fast-quenching method using the chemical formula: {50 wt% Na2B4O7.10 H2O–17 wt% CaO–17.5 wt% PbO–17.5 wt% As2O3} − x Cu2O3 where x = 0, 0.25, 0.5, 0.75, and 1g. Utilizing X-ray diffraction (XRD) patterns, electron spin resonance absorption (ESR), and Fourier transform infrared (FTIR) spectra, the interior structures of the prepared solids have been examined. Both XRD patterns and FTIR charts clarified that the amount of Cu2O3, in the range of 0–1g, did not affect the amorphous nature of Ca/Na lead-based Arseborate oxide glass, with the existence of four fundamental building units in each sample (BO3, BO4, PbO4, and AsO4). According to the optical characterization using UV–vis spectra, the increase in Cu2O3 concentration led to a decrease in optical energy gaps while increasing optical absorbance, optical reflectance, the plasmon frequency, calculated linear and nonlinear refractive indices, optical conductivity, and optoelectric conductivities. The results of the calculations and radioactive measurements indicated that the effective mass number increased as the amount of Cu2O3 content was increased, while the mean free path MFP and the half-value layer HVL decreased. According to the results, the examined glasses can be used as IR filters and shields. [ABSTRACT FROM AUTHOR]