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Spectroscopic and thermal analysis of lead-free multipurpose radiation shielding glasses
摘要： The genetic algorithm was used to identify glasses, of the composition 50Bi2O3-(50-x) B2O3-xBaO with wt.%, that have a similar half-value layer (HVL) and neutron removal cross-section. The structure of these glasses was further explored using a combination of spectroscopic and thermal analysis in order to ascertain whether they possess advantageous physical properties comparable to traditional materials used in nuclear reactor design. Differential scanning calorimetry (DSC) analysis was used to examine the thermal profile of the glass system and to identify glass transition temperature Tg and softening temperature Ts. Glass of the composition 50Bi2O3-30B2O3-20BaO had exhibited the highest thermal stability. Analysis of the Raman spectra of the samples confirmed the presence of BiO6 octahedrons and B-O-B bonds in poly borate chains. A deconvolution of the IR spectra was carried out to determine the relative proportions of BO3 triangles to BO4 tetrahedral units in the glass network that would affect the density and bulk modulus. Optical absorption spectrum of the samples exhibited absorption peaks in the blue region along with a broad band of absorption at longer red wavelengths associated with excitation of bismuth ions. When compared to traditional heavy concretes used in radiation shielding, the bismuth-barium borate glasses exhibited superior performance over conventional barite concrete as a gamma-radiation shield and was comparable to limonite concrete as a neutron radiation shield. The bulk modulus of the glass series was also found to be comparable to that of regular concrete at approximately to 30 GPa.
关键词： Half-value layer,Heavy metal oxide,Neutron removal cross-section,Genetic algorithm
更新于2025-09-10 09:29:36
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The structure, spectra and properties of Dy2O3 modified diamagentic lead-bismuth-germanium glasses
摘要： Dy2O3 is potential and attractive as scintillator, mid infrared laser and Faraday rotation materials in high energy physics, general radiation and magneto optical sensing systems. In this study, Dy3+ doped diamagnetic glasses with compositions of 10GeO2 – 30PbO – 50Bi2O3 – (10-x)B2O3 –xDy2O3 (x = 0, 0.5, 1, 2, 3, 5 M %) were fabricated by a melt quenching technique. The modification of Dy3+on glass forming, structure, UV–Vis, FT-IR, Raman and photoluminescence spectra and properties were investigated through XRD, Raman spectra, DSC, Vicker's hardness and Verdet constant measurements etc. Melt with Dy2O3 content beyond 5% prefer to crystallize, not to form glassy matrix. The UV visible absorption spectra showed three intense bands at 483 nm, 575 nm and 661 nm due to 4F9/2 → 6H15/2 (blue), 4F9/2 → 6H13/2 (yellow) and 4F9/2 → 6H11/2 (red) transitions, respectively. Judd-Ofelt paramaters have been calculated to verify network connectivity of Dy2O3 doped glasses. FT-IR and Raman spectrum depicted the presence of PbO4, BiO3, GeO6, BO3 frame groups and DyeO bonds from cubit Dy2O3. Glass doped with 1%Dy2O3 exhibited promising thermal stability (97 °C), microhardness (480 HV) and magneto-optical activity (0.1864 min/G.cm@532 nm) due to the high optical dispersion, high ion polarizability of Dy3+ ions
关键词： Heavy metal oxide glass,Faraday rotation,Dy2O3,Diamagnetic glass
更新于2025-09-04 15:30:14