Radiation shielding and mechanical properties of Bi2O3–Na2O–TiO2–ZnO–TeO2 glass system

Investigation of the Effect of PbO Doping on Telluride Glass Ceramics as a Potential Material for Gamma Radiation Shielding

The purpose of this paper is to study the effect of PbO doping of multicomponent composite glass-like ceramics based on TeO₂, WO₃, Bi₂O₃, MoO₃, and SiO₂, which are one of the promising materials for gamma radiation shielding. According to X-ray diffraction data, it was found that the PbO dopant concentration increase from 0.10 to 0.20-0.25 mol results in the initialization of the phase transformation and structural ordering processes, which are expressed in the formation of SiO₂ and PbWO₄ phases, and the crystallinity degree growth. An analysis of the optical properties showed that a change in the ratio of the contributions of the amorphous and ordered fractions leads to the optical density increase and the band gap alteration, as well as a variation in the optical characteristics. During the study of the strength and mechanical properties of the synthesized ceramics, depending on the dopant concentration, it was found that when inclusions in the form of PbWO₄ are formed in the structure, the strength characteristics increase by 70-80% compared to the initial data, which indicates the doping efficiency and a rise in the mechanical strength of ceramics to external influences. During evaluation of the shielding protective characteristics of the synthesized ceramics, it was revealed that the formation of PbWO₄ in the structure results in a rise in the high-energy gamma ray absorption efficiency.

Investigation of the Efficiency of Shielding Gamma and Electron Radiation Using Glasses Based on TeO2-WO3-Bi2O3-MoO3-SiO to Protect Electronic Circuits from the Negative Effects of Ionizing Radiation

This article considers the effect of MoO₃ and SiO additives in telluride glasses on the shielding characteristics and protection of electronic microcircuits operating under conditions of increased radiation background or cosmic radiation. MoO₃ and SiO dopants were chosen because their properties, including their insulating characteristics, make it possible to avoid breakdown processes caused by radiation damage. The relevance of the study consists in the proposed method of using protective glasses to protect the most important components of electronic circuits from the negative effects of ionizing radiation, which can cause failures or lead to destabilization of the electronics. Evaluation of the shielding efficiency of gamma and electron radiation was carried out using a standard method for determining the change in the threshold voltage (∆U) value of microcircuits placed behind the shield and subjected to irradiation with various doses. It was established that an increase in the content of MoO₃ and SiO in the glass structure led to an increase of up to 90% in the gamma radiation shielding efficiency, while maintaining the stability of microcircuit performance under prolonged exposure to ionizing radiation. The results obtained allow us to conclude that the use of protective glasses based on TeO₂-WO₃-Bi₂O₃-MoO₃-SiO is highly promising for creating local protection for the main components of microcircuits and semiconductor devices operating under conditions of increased background radiation or cosmic radiation.

The Interrelation of Synthesis Conditions and Wettability Properties of the Porous Anodic Alumina Membranes

The results of studies on the wettability properties and preparation of porous anodic alumina (PAA) membranes with a 3.3 ± 0.2 μm thickness and a variety of pore sizes are presented in this article. The wettability feature results, as well as the fabrication processing characteristics and morphology, are presented. The microstructure effect of these surfaces on wettability properties is analyzed in comparison to outer PAA surfaces. The interfacial contact angle was measured for amorphous PAA membranes as-fabricated and after a modification technique (pore widening), with pore sizes ranging from 20 to 130 nm. Different surface morphologies of such alumina can be obtained by adjusting synthesis conditions, which allows the surface properties to change from hydrophilic (contact angle is approximately 13°) to hydrophobic (contact angle is 100°). This research could propose a new method for designing functional surfaces with tunable wettability. The potential applications of ordinary alumina as multifunctional films are demonstrated.

Structural Study of Nano-Clay and Its Effectiveness in Radiation Protection against X-rays

With the increasing applications of nuclear technology, radiation protection has become very important especially for the environment and the personnel close to radiation sources. Natural clays can be used potentially for shielding the X-ray radiations. In this study, the correlation between structural parameters and radiation shielding performance of natural clay extracted from Algerian Sahara (Adrar, Reggan, and Timimoune) was investigated. Phase composition and structural parameters (lattice parameters, average crystallite size, and microstrain) were determined by the Rietveld refinements of X-ray diffraction patterns in the frame of HighScore Plus software. The obtained results showed that the studied clays are nanocrystalline (nano-clay) since the calculated crystallite size was ≈3 nm for the feldspar phase. FTIR spectra confirmed the presence of all phases already detected by XRD analysis besides Biotite (around the band at 3558 cm⁻¹). The remaining bands corresponded to absorbed and adsorbed water (3432 cm⁻¹ and 1629 cm⁻¹, respectively) and atmospheric CO₂ (2356 cm⁻¹). The shielding properties (mass absorption coefficient—µ/ρ and radiative attenuation rate—RA) for (green-yellow, green, and red) clays of Adrar, (red, white, and white-red) clays of Reggan, and red clay of Timimoune at same energy level were examined. The results of clay samples were compared with each other. The obtained results indicated that the green clay of Adrar exhibited the superior radiation shielding, i.e., 99.8% and 243.4 cm²/g for radiative attenuation rate and mass absorption coefficient, respectively.

Bi-Function TiO2:Yb3+/Tm3+/Mn2+-Assisted Double-Layered Photoanodes for Improving Efficiency of Dye-Sensitized Solar Cells

A bi-function TiO2:Yb3+/Tm3+/Mn2+-assisted double-layered photoanode was designed to improve the efficiency of dye-sensitized solar cells (DSSCs). The scanning electron microscopy (SEM) results show that the introduction of Mn2+ ions leads to smaller-sized TiO2:Yb3+/Tm3+/Mn2+ nanospheres, which is changed from nanosheet-shaped TiO2 and TiO2:Yb3+/Tm3+. Based on Scherrer’s formula from the X-ray diffraction (XRD) peak (101), the crystallite sizes decrease due to the introduction of Mn2+ ions. By utilizing screen-printing techniques, DSSCs fabricated by bi-function TiO2:Yb3+/Tm3+/Mn2+-assisted double-layered photoanodes exhibit the short-circuit current density (Jsc) of 15.68 mA/cm2, open-circuit voltage (Voc) of 0.67 V, fill factor (FF) of 0.71 and the power conversion efficiency (PCE) of 7.41%. The PCE of our designed DSSC is higher than that of DSSCs with a TiO2/TiO2 photoanode (6.84%), which is attributed to the bi-function effects of TiO2:Yb3+/Tm3+/Mn2+ including the conversion of NIR into visible light and improved light scattering. An increased charge transfer resistance of the photoanode/electrolyte interface indicates the suppressed charge recombination of electrons with the electrolyte redox couple (I−/I3−) in DSSCs with a TiO2/TiO2:Yb3+/Tm3+/Mn2+ double-layered photoanode, which also contributes to the enhanced performance of DSSCs. The double-layered photoanode fabricated by bi-function TiO2:Yb3+/Tm3+/Mn2+ nanospheres will provide a promising avenue for moving DSSCs forward to meet practical applications.

Isostatic Hot Pressed W–Cu Composites with Nanosized Grain Boundaries: Microstructure, Structure and Radiation Shielding Efficiency against Gamma Rays

The W–Cu composites with nanosized grain boundaries and high effective density were fabricated using a new fast isostatic hot pressing method. A significantly faster method was proposed for the formation of W–Cu composites in comparison to the traditional ones. The influence of both the high temperature and pressure conditions on the microstructure, structure, chemical composition, and density values were observed. It has been shown that W–Cu samples have a polycrystalline well-packed microstructure. The copper performs the function of a matrix that surrounds the tungsten grains. The W–Cu composites have mixed bcc-W (sp. gr. Im 3¯ m) and fcc-Cu (sp. gr. Fm 3¯ m) phases. The W crystallite sizes vary from 107 to 175 nm depending on the sintering conditions. The optimal sintering regimes of the W–Cu composites with the highest density value of 16.37 g/cm³ were determined. Tungsten–copper composites with thicknesses of 0.06–0.27 cm have been fabricated for the radiation protection efficiency investigation against gamma rays. It has been shown that W–Cu samples have a high shielding efficiency from gamma radiation in the 0.276–1.25 MeV range of energies, which makes them excellent candidates as materials for radiation protection.

Mechanical properties, elastic moduli, transmission factors, and gamma-ray-shielding performances of Bi2O3–P2O5–B2O3–V2O5 quaternary glass system

Mechanical properties, elastic moduli, transmission factors (TFs), and gamma-ray shielding performance of quaternary glass systems with chemical composition (0.25−x)Bi2O3–xB2O3−0.75(50%P2O5−50%V2O5), where x = 0.05 (S1), 0.10 (S2), 0.15 (S3), and 0.20 (S4) mol%, were comprehensively studied. The MCNPX code, Phy-X/PSD software, and the Makishima–Mackenzie model were utilized to achieve the mentioned purposes. The values of the packing density (V t) decreased from 0.634432 to 0.600611, while those of the dissociation energy (G t) increased from 51.6125 kJ/cm3 for the S1 glass sample (with Bi2O3 = 5 mol%) to 56.7525 kJ/cm3 for the S4 glass sample (with Bi2O3 = 20 mol%). This means that the mechanical properties were enhanced by increasing the Bi2O3 content in glasses. Linear (µ) and mass attenuation (µ m) coefficients for the S4 glass sample were the greatest compared to those for glass materials investigated, i.e., (µ, µ m)S1 < (µ, µ m)S2 < (µ, µ m)S3 < (µ, µ m)S4. Half- and tenth-value layers (HVL and TVL, respectively) follow the trend: (HVL, TVL)S1 > (HVL, TVL)S2 > (HVL, TVL)S3 > (HVL, TVL)S4. The effective atomic number (Z eff) of investigated glasses has the same trend as of linear and mass attenuation coefficients. Our findings indicate that increasing the amount of Bi2O3 reinforcement decreased the exposure buildup factor and energy absorption buildup factor values for all mean free path values (0.5–40 mfp). All glasses recorded the minimum TF values at a thickness of 3 cm. The findings would benefit the scientific community in determining the most appropriate additive bismuth(iii) oxide/diboron trioxide type and related glass composition to provide the shielding properties previously mentioned in terms of needs and utilization requirements, as well as the most suitable glass composition.

Examinations the optical, mechanical, and shielding properties of Ag2O doped B2O3-Bi2O3-SrF2-Na2O glasses for gamma ray shield applications

A series of five glass samples have a chemical composition of (55-x) B₂O₃ + 5 Bi₂O₃ + 20SrF₂ + 20Na₂O + xAg₂O with varied doping ratios x = 0, 1, 2, 3, and 4 mol% were fabricated using the melt quenching technique to study the effect of B₂O₃ replacement by Ag₂O on the physical, mechanical, optical and gamma-ray shielding capacity of the fabricated glasses. The Cary 5000 UV–Vis–NIR measured the optical absorption in the wavelength range between 200 and 3000 nm. Based on the measured optical absorption, energy (direct/indirect) bandgap and Urbach energy were calculated. Moreover, the measured samples density, molar volume, packing density, dissociation energy, and mechanical properties for the fabricated glasses were calculated using the concepts of the Makishima-Mackenzie model. In this regard, the microhardness was decreased from 4.070 to 3.931 GPa with raising the Ag₂O concentration. The effect of B₂O₃ replacement on the shielding capacity was also evaluated using the Monte Carlo simulation. The simulation results showed that the replacement of B₂O₃ causes a significant increase in the shielding parameters like linear attenuation coefficient and radiation shielding capacity. The best radiation shielding properties were achieved for a glass sample with 4 mol% Ag₂O compound. Its linear attenuation coefficient varied between 8.091 and 0.134 cm⁻¹, raising the gamma photon energy between 0.059 and 2.506 MeV.

Energy Retention in Thin Graphite Targets after Energetic Ion Impact

High energy ion irradiation is an important tool for nanoscale modification of materials. In the case of thin targets and 2D materials, which these energetic ions can pierce through, nanoscale modifications such as production of nanopores can open up pathways for new applications. However, materials modifications can be hindered because of subsequent energy release via electron emission. In this work, we follow energy dissipation after the impact of an energetic ion in thin graphite target using Geant4 code. Presented results show that significant amount of energy can be released from the target. Especially for thin targets and highest ion energies, almost 40% of deposited energy has been released. Therefore, retention of deposited energy can be significantly altered and this can profoundly affect ion track formation in thin targets. This finding could also have broader implications for radiation hardness of other nanomaterials such as nanowires and nanoparticles.

Growth and Characterization of Ce-Doped Luag Single Crystal Fibers from Transparent Ceramics by Laser-Heated Pedestal Method

Scintillation single crystal fibers (SCFs) have great potential applications in the new generation of high-energy ray and particle detectors due to their morphological advantages. In this work; Ce:LuAG SCFs with a diameter of 1 mm were grown along the direction of [111] by laser-heated pedestal growth (LHPG) method using a transparent ceramic as the source rod; and a doping concentration was 0.1 at%, 0.3 at%, 1 at%, respectively. The effects of growth rate and annealing in air on the scintillation and optical properties of SCF are discussed in detail. The results of analyzing the absorption spectra; radioluminescence (RL) spectra; pulse-height spectra and fluorescence lifetime of SCFs show that the SCF maintains excellent scintillation performance while having a fiber structure. Therefore; Ce:LuAG SCF is a potential candidate material for detector.

The Role of La2O3 in Enhancement the Radiation Shielding Efficiency of the Tellurite Glasses: Monte-Carlo Simulation and Theoretical Study

The radiation shielding competence was examined for a binary glass system xLa₂O₃ + (1 - x) TeO₂ where x = 5, 7, 10, 15, and 20 mol% using MCNP-5 code. The linear attenuation coefficients (LACs) of the glasses were evaluated, and it was found that LT20 glass has the greatest LAC, while LT5 had the least LAC. The transmission factor (TF) of the glasses was evaluated against thicknesses at various selected energies and was observed to greatly decrease with increasing thickness; for example, at 1.332 MeV, the TF of the LT5 glass decreased from 0.76 to 0.25 as the thickness increased from 1 to 5 cm. The equivalent atomic number (Z_eq) of the glasses gradually increased with increasing photon energy above 0.1 MeV, with the maximum values observed at around 1 MeV. The buildup factors were determined to evaluate the accumulation of photon flux, and it was found that the maximum values for both can be seen at around 0.8 MeV. This research concluded that LT20 has the greatest potential in radiation shielding applications out of the investigated glasses due to the glass having the most desirable parameters.