Optimizing gamma radiation shielding with cobalt-titania hybrid nanomaterials.

Cobalt-doped titania nanocomposites were fabricated to be utilized for radiation shielding aims. The chemical composition of the composites was measured using the energy-dispersive X-ray spectrometer. Moreover, the structure of the composites was evaluated using the X-ray diffractometer, and the morphology of the fabricated composites was presented using the scanning electron microscope. Furthermore, the γ-ray shielding properties were estimated using the Monte Carlo simulation between 0.059 and 2.506 MeV. The linear attenuation coefficient of the fabricated composites decreased by factors of 93% for all samples by raising the incident γ-energy between 0.059 and 2.506 MeV. Moreover, the partial replacement of the Ti4+ by Co3+ slightly enhanced the linear attenuation coefficient from 0.607 to 0.630 cm-1 when the Co3+ increased from 0 to 3.7 wt%. The improvement in the linear attenuation coefficient causes an enhancement in other radiation shielding properties.

Grafting red clay with Bi2O3 nanoparticles into epoxy resin for gamma-ray shielding applications.

We developed new composites for photons shielding applications. The composite were prepared with epoxy resin, red clay and bismuth oxide nanoparticles (Bi2O3 NPs). In order to establish which ratio of red clay to Bi2O3 NPs provides the best shielding capabilities, several different ratios of red clay to Bi2O3 NPs were tested. The transmission factor (TF) was calculated for two different thicknesses of each sample. From the TF data, we found that epoxy resin materials have a high attenuation capacity at low energy. For ERB-10 sample (40%Epoxy + 50% Red clay + 10% Bi2O3 NPs), the TF values are 52.3% and 14.3% for thicknesses of 0.5 and 1.5 cm (at 0.06 MeV). The composite which contains the maximum amount of Bi2O3 nanoparticles (40%Epoxy + 50% Red clay + 10% Bi2O3 NPs, coded as ERB-30) has lower TF than the other composites. The TF data demonstrated that ERB-30 is capable of producing more effective attenuation from gamma rays. We also determined the linear attenuation coefficient (LAC) for the prepared composites and we found that the LAC increases for a given energy in proportion to the Bi2O3 NPs ratio. For the ERB-0 (free Bi2O3 NPs), the LAC at 0.662 MeV is 0.143 cm-1, and it increases to 0.805 cm-1 when 10% of Bi2O3 NPs is added to the epoxy resin composite. The half value layer (HVL) results showed that the thickness necessary to shield that photons to its half intensity can be significantly lowered by increasing the weight fraction of the Bi2O3 NPs in the epoxy resin composite from 0 to 30%. The HVL for ERB-20 and ERB-30 were compared with other materials such as (Epoxy as a matrix material and Al2O3, Fe2O3, MgO and ZrO2 as filler oxides in the matrix at 0.662 MeV. The HVL values for ERB-20 and ERB-30 are 4.385 and 3.988 cm and this is lower than all the selected epoxy polymers.

Morphological and Gamma-Ray Attenuation Properties of High-Density Polyethylene Containing Bismuth Oxide.

For extensive radiation exposure, inventing a novel radiation shielding material is a burning issue at present for the purpose of life saving. Considering this thought, in this study, by adding sundry amounts of Bi2O3 into pure high-density polyethylene (HDPE), six HDPE systems were prepared to evaluate the radiation shielding efficiency. These HDPE systems were HDPEBi-0 (pure HDPE), HDPEBi-10 (10 wt% Bi2O3), HDPEBi-20 (20 wt% Bi2O3-), HDPEBi-30 (30 wt% Bi2O3), HDPEBi-40 (40 wt% Bi2O3), and HDPEBi-50 (50 wt% Bi2O3). The values of the linear attenuation coefficients of the experimental results (calculated in the lab using HPGe) were compared with the theoretical results (obtained using Phy-X software) at 0.060, 0.662, 1.173, and 1.333 MeV energies. To ensure the accurateness of the experimental results, this comparison was made. It was crystal clear that for energy values from 0.06 MeV to 1.333 MeV, all the experimental values were in line with Phy-X software data, which demonstrated the research setup's reliability. Here, the linear attenuation coefficient (LAC), and mean free path (MFP) shielding parameters were assessed. At the energy of 1.333 MeV, sample HDPEBi-0 showed an HVL value 1.7 times greater than that of HDPEBi-50, yet it was 23 times greater at 0.0595 MeV. That means that for proper radiation protection, very-low-energy HDPE systems containing 10-50% Bi2O3 could be used; however, the thickness of the HDPE system must be increased according to the energy of incident radiation.

Bi and Sn Doping Improved the Structural, Optical and Photovoltaic Properties of MAPbI3-Based Perovskite Solar Cells.

One of the most amazing photovoltaic technologies for the future is the organic-inorganic lead halide perovskite solar cell, which exhibits excellent power conversion efficiency (PCE) and can be produced using a straightforward solution technique. Toxic lead in perovskite can be replaced by non-toxic alkaline earth metal cations because they keep the charge balance in the material and some of them match the Goldschmidt rule's tolerance factor. Therefore, thin films of MAPbI3, 1% Bi and 0%, 0.5%, 1% and 1.5% Sn co-doped MAPbI3 were deposited on FTO-glass substrates by sol-gel spin-coating technique. XRD confirmed the co-doping of Bi-Sn in MAPbI3. The 1% Bi and 1% Sn co-doped film had a large grain size. The optical properties were calculated by UV-Vis spectroscopy. The 1% Bi and 1% Sn co-doped film had small Eg, which make it a good material for perovskite solar cells. These films were made into perovskite solar cells. The pure MAPbI3 film-based solar cell had a current density (Jsc) of 9.71 MA-cm-2, its open-circuit voltage (Voc) was 1.18 V, its fill factor (FF) was 0.609 and its efficiency (η) was 6.98%. All of these parameters were improved by the co-doping of Bi-Sn. The cell made from a co-doped MAPbI3 film with 1% Bi and 1% Sn had a high efficiency (10.03%).

The Effect of 600 keV Ag Ion Irradiation on the Structural, Optical, and Photovoltaic Properties of MAPbBr3 Films for Perovksite Solar Cell Applications.

A competitive new technology, organic metallic halide perovskite solar cells feature a wide working area, low manufacturing costs, a long lifespan, and a significant amount of large efficacy of power conversion (PCE). The spin-coating technique was utilized for the fabrication of pure CH3NH3PbBr3 (MAPbBr3) thin films, and these films are implanted with 600 keV silver (Ag) ions at fluency rate of 6 × 1014 and 4 × 1014 ions/cm2. XRD analysis confirmed the cubic structure of MAPbBr3. A high grain size was observed at the fluency rate of 4 × 1014 ions/cm2. The UV-Vis spectroscopic technique was used to calculate the optical properties such as the bandgap energy (Eg), refractive index (n), extinction coefficients (k), and dielectric constant. A direct Eg of 2.44 eV was measured for the pristine film sample, whereas 2.32 and 2.36 eV were measured for Ag ion-implanted films with a 4 × 1014 and 6 × 1014 ions/cm2 fluence rate, respectively. The solar cells of these films were fabricated. The Jsc was 6.69 mA/cm2, FF was 0.80, Voc was 1.1 V, and the efficiency was 5.87% for the pristine MAPbBr3-based cell. All of these parameters were improved by Ag ion implantation. The maximum values were observed at a fluency rate of 4 × 1014 ions/cm2, where the Voc was 1.13 V, FF was 0.75, Jsc was 8.18 mA/cm2, and the efficiency was 7.01%.

Investigation of the Gamma-ray Shielding Performance of CuO-CdO-Bi2O3 Bentonite Ceramics.

The purpose of this research is to identify the radiation shielding capability of ceramics adding CuO, CdO, and Bi2O3 with diverse wt (%). The chemical compositions of the raw ceramics were documented through Energy Dispersive X-ray "EDX" techniques. For aesthetic appeal and solidification, CuO has been chosen to be added to ceramic. Moreover, in the interest of increasing the radiation shielding ability, the high atomic number and density of both CdO and Bi2O3 were suggested for the raw ceramics. To obtain the morphological features of the prepared ceramic samples, a Scanning Electron Microscope, or SEM, was utilized. To verify the experimental results, the MCA value obtained from the Phy-X software was compared to the experimental value collected from the HPGe detector. At energies 0.06 MeV, 0.662 MeV, 1.173 MeV, and 1.333 MeV the linear and mass attenuation coefficients of the prepared ceramics have been measured using a high purity germanium "HPGe" detector as well as three different point sources. Moreover, the relationship between ln(I) and the thickness of the ceramics has been presented here, and the comparison between the LAC of the prepared ceramics with other materials has also been displayed. Bentonite ceramic containing CuO (15 mol %)-CdO (15 mol %)-Bi2O3 (20 mol %) with density 3.6 showed the lowest HVL, MFP, and TVL at all studied energies, yet pure Bentonite ceramic containing only CuO (50 mol %), having density 3.4, presented the greatest values. Hence, it can be concluded that the addition of CdO and Bi2O3 enhances the radiation shielding ability.

Impact of ZnO Modifier Concentration on TeO2 Glass Matrix for Optical and Gamma-Ray Shielding Capabilities.

This study carried out a comparison of the optical and gamma ray shielding features of TeO2 with and without ZnO modifier concentration. Incorporating ZnO into the TeO2 network reduces the indirect band gap from 3.515-3.481 eV. When ZnO is added, refractive indices, dielectric constants, and optical dielectric constants rise from 2.271-2.278, 5.156-5.191, and 4.156-4.191 accordingly. The transmission coefficient and reflection loss are in direct opposition to each other. With increasing ZnO concentration in the selected glasses, the values of molar refractivity and molar polarizability decrease from 18.767-15.018 cm3/mol and from 7.444 × 10-24-5.957 × 10-24 cm3, respectively, while the electronic polarizability rises from 8.244 × 1024-8.273 × 1024, correspondingly. As expected by the metallization values, the glass systems are non-metallic. The linear attenuation coefficients (LAC) of the studied glass samples ensue through enhancing the photon energy range 0.0395-0.3443 MeV. There is a very slow decrease in the LAC from an energy of 0.1218-0.3443 MeV, yet there is a sharp decrease from an energy of 0.0401-0.0459 MeV. According to the obtained values of numerous shielding parameters such as LAC, MAC, HVL, MFP, and Zeff sample, Zn30 has shown the best radiation shielding ability comprising other studied samples.

Impact of WO3-Nanoparticles on Silicone Rubber for Radiation Protection Efficiency.

Silicone rubbers are a good choice for shielding materials because of having elastic and attenuating properties as well as cost-effectiveness. Thus, the aim of this study was to prepare ground-breaking silicone rubber samples by adding WO3-nanoparticles and testing the performance of their radiation shielding ability against Cs-137, Co-60, and Am-241 gamma energy. Increasing the concentration of WO3 nanoparticles in silicone rubber (SR) led to decreasing the half-value layer (HVL) and mean free path (MFP) values determined for the samples tested. Furthermore, the values of MFP and HVL upsurged according to the enhancement of the photon energy. It is noteworthy that the prepared silicone rubber (SR) systems with 50 and 60 wt% concentrations of WO3-nanoparticles displayed lower HVL than the Bi2O3-containing silicone rubber (SR) systems. In the same way, studied silicone rubber SR-W60 represented the lowest HVL comprising iron ore containing silicone rubber.

Design and Gamma-Ray Attenuation Features of New Concrete Materials for Low- and Moderate-Photons Energy Protection Applications.

We aimed, in this investigation, to prepare novel concretes which can be used in gamma-ray shielding applications. The experimental approach was performed using a NaI (Tl) detector to measure the concrete's shielding features for different energies, ranging from 0.081 MeV to 1.408 MeV. The density of the fabricated concretes decreased with increasing W/C ratio, where the density decreased by 2.680 g/cm3, 2.614 g/cm3, and 2.564 g/cm3 for concretes A, B, and C, respectively, with increases in the W/C ratio of 0.4, 0.6, and 0.8, respectively. When the energy was elevated between 0.08 MeV and 1.408 MeV, the highest values were attained for concrete A, with values ranging between 0.451 cm-1 and 0.179 cm-1. The lowest half-value layer (Δ0.5) values were achieved for concrete C, where the Δ0.5 values varied between 1.53 cm and 3.86 cm between 0.08 MeV and 1.408 MeV. The highest Δ0.5 values were achieved for concrete A, where the Δ0.5 varied between 1.77 cm and 4.67 cm between 0.08 MeV and 1.408 MeV. According to this investigation, concrete A has the highest promise in radiation shielding purposes because it has the most desirable properties of the concretes studied.

Determination of 238U and 40K Radionuclide Concentrations in Some Granite Rocks by Gamma Spectroscopy and Energy Dispersive X-ray Analysis.

Uranium-238 (238U) and potassium-40 (40K) are important naturally occurring radionuclides. Gamma spectroscopy is a direct, non-destructive method used to determine radionuclide concentrations, but it suffers from the interference of gamma lines. 40K gamma spectroscopy is affected by background interference, which leads to a reduction in the minimum detectable activity. The energy dispersive X-ray analytical technique is quick, with fewer interference problems or background effects. However, it is an indirect method for calculating and deducing the concentrations of isotopes. The aim of the present study was to compare and evaluate both techniques so that they can be utilized efficiently. The results of 238U and 40K were measured by well-calibrated gamma spectroscopy and energy dispersive X-ray techniques. the results indicated that Halayeb White granite is the most environmentally safe compared to the other two types because it contains a very low concentration of uranium 238 and potassium 40.

A Study on the Gamma Radiation Protection Effectiveness of Nano/Micro-MgO-Reinforced Novel Silicon Rubber for Medical Applications.

In this work, we examined novel polymer composites for use in radiation protection applications. These prepared polymers are non-toxic compared with lead and show potential to be used as protective gear in different medical applications where low-energy photons are utilized. We prepared silicon rubber (SR) with different concentrations of micro- and nano-sized MgO. We used a HPGe detector to measure radiation attenuation factors at different photon energies, ranging from 59.6 to 1333 keV. We reported the effect of particle size on the attenuation parameters and found that the linear attenuation factors for SR with nano-MgO were higher than for SR with micro-MgO. The mean free path (MFP) for pure SR and SR with micro- and nano-sized MgO were determined, and we found that silicon rubber with MgO (both micro- and nano-sized) has a lower MFP than pure SR. The linear attenuation coefficient results show the importance of using SR with high MgO content for low-energy radiation protection applications. Moreover, the half-value layer (HVL) results demonstrate that we need a certain thickness of SR with nano-MgO to effectively reduce the intensity of the low-energy photons.

Effect of Gamma Irradiation on the Structural, Optical, Electrical, and Ferroelectric Characterizations of Bismuth-Modified Barium Titanate Ceramics.

Materials with ferroelectric properties, low bandgap energies, high polarization, low loss, and thermal stability are essential for future solar-cell applications. Researchers have attempted to obtain such materials by using several approaches. In this vein, a novel approach is reported in this work using gamma ray irradiation. The effect of gamma radiation on the structural, optical, and ferroelectric characterizations of bismuth (Bi)-doped barium titanate (BaTiO3 (BT)), namely Ba0.95Bi0.05TiO3 ceramics (abbreviated as (Bi:BT)), was investigated. X-ray diffraction, structure refinement, and Raman study revealed the presence of a perovskite structure with a tetragonal phase in all investigated samples. Morphological study revealed a nonuniform grain size and some porosity. Gamma irradiation-induced combined effects were proved by a detailed analysis of bond lengths, bond angles, octahedral distortions, oxygen vacancies, and charge compensations. Electron paramagnetic resonance (EPR) study gave direct evidence of oxygen vacancies in the irradiated samples. After gamma irradiation, UV-vis study indicated a decrease in the bandgap from 3.14 to 2.80 eV and a significant increase in visible light absorption. Cole-Cole plots confirm as an increase in gamma-ray dose results in higher levels of electron hopping. Study of the P-E hysteresis loop demonstrated that ferroelectric properties could be maintained after gamma irradiation, with a slight decrease in remnant polarization. The behaviour of the P-E was correlated with increasing gamma dose in the investigated ceramics, demonstrating a strong gamma dependence in the loops' profile. We guess that the present approach may be a promising technique for enhancing the multifunctionality of electronic devices.

Conversion of Sewage Water into H2 Gas Fuel Using Hexagonal Nanosheets of the Polyaniline-Assisted Deposition of PbI2 as a Nanocomposite Photocathode with the Theoretical Qualitative Ab-Initio Calculation of the H2O Splitting.

This study is very promising for providing a renewable enrgy (H2 gas fuel) under the elctrochemical splitting of the wastwater (sewage water). This study has double benefits: hydrogen generation and contaminations removel. This study is carried out on sewage water, third stage treated, from Beni-Suef city, Egypt. Antimony tin oxide (ATO)/polyaniline (PANI)/PbI2 photoelectrode is prepared through the in situ oxidative polymerization of PANI on ATO, then PANI is used as an assistant for PbI2 deposition using the ionic adsorption deposition method. The chemical structural, morphological, electrical, and optical properties of the composite are confirmed using different analytical tools such as X-ray diffreaction (XRD), scanning electron microscope (SEM), transmision electron microscope (TEM), Fourier-transform infrared spectroscopy (FTIR), and UV-Vis spectroscopy. The prepared PbI2 inside the composite has a crystal size of 33 nm (according to the peak at 12.8°) through the XRD analyses device. SEM and TEM confirm the hexagonal PbI2 sheets embedded on the PANI nanopores surface. Moreover, the bandgap values are enhanced very much after the composite formation, in which the bandgap values for PANI and PANI/PbI2 are 3 and 2.51 eV, respectively. The application of ATO/PANI/PbI2 nanocomposite electrode for sewage splitting and H2 generation is carried out through a three-electrode cell. The measurements carreid out using the electrocehical worksattion under th Xenon lamp (100 mW.cm-2). The produced current density (Jph) is 0.095 mA.cm-2 at 100 mW.cm-2 light illumination. The photoelectrode has high reproducibility and stability, in which and the number of H2 moles is 6 µmole.h-1.cm-1. The photoelectrode response to different monochromatic light, in which the produced Jph decreases from 0.077 to 0.072 mA.cm-2 with decreasing of the wavelengths from 390 to 636 nm, respectively. These values confirms the high response of the ATO/PANI/PbI2 nanocomposite electrode for the light illuminaton and hydrogen genration under broad light region. The thermodynamic parameters: activation energy (Ea), enthalpy (ΔH*), and entropy (ΔS*) values are 7.33 kJ/mol, -4.7 kJ/mol, and 203.3 J/mol.K, respectively. The small values of ΔS* relted to the high sesnivity of the prepared elctrode for the water splitting and then the hydrogen gneration. Finally, a theoretical study was mentioned for calculation geometry, electrochemical, and thermochemistry properties of the polyaniline/PbI2 nanocomposite as compared with that for the polyaniline.

Structural and Magnetic Phase Transitions in BiFe1 - xMnxO3 Solid Solution Driven by Temperature.

The crystal structure and magnetic state of the (1 − x)BiFeO3-(x)BiMnO3 solid solution has been analyzed by X-ray diffraction using lab-based and synchrotron radiation facilities, magnetization measurements, differential thermal analysis, and differential scanning calorimetry. Dopant concentration increases lead to the room-temperature structural transitions from the polar-active rhombohedral phase to the antipolar orthorhombic phase, and then to the monoclinic phase accompanied by the formation of two-phase regions consisting of the adjacent structural phases in the concentration ranges 0.25 < x1 < 0.30 and 0.50 ≤ x2 < 0.65, respectively. The accompanied changes in the magnetic structure refer to the magnetic transitions from the modulated antiferromagnetic structure to the non-colinear antiferromagnetic structure, and then to the orbitally ordered ferromagnetic structure. The compounds with a two-phase structural state at room temperature are characterized by irreversible temperature-driven structural transitions, which favor the stabilization of high-temperature structural phases. The magnetic structure of the compounds also exhibits an irreversible temperature-induced transition, resulting in an increase of the contribution from the magnetic phase associated with the high-temperature structural phase. The relationship between the structural parameters and the magnetic state of the compounds with a metastable structure is studied and discussed depending on the chemical composition and heating prehistory.

A Study of Ta2O5 Nanopillars with Ni Tips Prepared by Porous Anodic Alumina Through-Mask Anodization.

The paper discusses the formation of Ta2O5 pillars with Ni tips during thin porous anodic alumina through-mask anodization on Si/SiO2 substrates. The tantalum nanopillars were formed through porous masks in electrolytes of phosphoric and oxalic acid. The Ni tips on the Ta2O5 pillars were formed via vacuum evaporation through the porous mask. The morphology, structure, and magnetic properties at 4.2 and 300 K of the Ta2O5 nanopillars with Ni tips have been studied using scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry. The main mechanism of the formation of the Ta2O5 pillars during through-mask anodization was revealed. The superparamagnetic behavior of the magnetic hysteresis loop of the Ta2O5 nanopillars with Ni tips was observed. Such nanostructures can be used to develop novel functional nanomaterials for magnetic, electronic, biomedical, and optical nano-scale devices.

Structure, Morphology and Electrical/Magnetic Properties of Ni-Mg Nano-Ferrites from a New Perspective.

Using the auto combustion flash method, Ni1-x+2Mgx+2Fe2+3O4 (x = 0, 0.2, 0.6, 0.8 and 1) nano-ferrites were synthesized. All samples were thermally treated at 973 K for 3 h. The structural analysis for the synthesized samples was performed using XRD, high-resolution transmission electron microscopy (HRTEM), and FTIR. Scanning electron microscopy (SEM) was undertaken to explore the surface morphology of all the samples. The thermal stability of these samples was investigated using thermogravimetric analysis (TGA). XRD data show the presence of a single spinel phase for all the prepared samples. The intensity of the principal peak of the spinel phase decreases as Mg content increases, showing that Mg delays crystallinity. The Mg content raised the average grain size (D) from 0.084 µm to 0.1365 µm. TGA shows two stages of weight loss variation. The vibrating sample magnetometer (VSM) measurement shows that magnetic parameters, such as initial permeability (µi) and saturation magnetization (Ms), decay with rising Mg content. The permeability and magnetic anisotropy at different frequencies and temperatures were studied to show the samples' magnetic behavior and determine the Curie temperature (TC), which depends on the internal structure. The electrical resistivity behavior shows the semi-conductivity trend of the samples. Finally, the dielectric constant increases sharply at high temperatures, explained by the increased mobility of charge carriers, and decreases with increasing frequency.

Photovoltaic Properties of ZnO Films Co-Doped with Mn and La to Enhance Solar Cell Efficiency.

In the present investigation, ZnO films co-doped with Mn and La were synthesized by the sol-gel technique. XRD analysis revealed that ZnO had a hexagonal structure. Mixed hexagonal and cubic phases appeared in ZnO containing Mn (1%) and La (1.5%). The grain size, d-spacing, unit cell, lattice parameters, atomic packing fraction, volume, strain, crystallinity, and bond length of co-doped ZnO films were determined as a function of doped ion contents. Through UV analysis, it was found that pristine ZnO had Eg = 3.5 eV, and it decreased when increasing the doping concentration, reaching the minimum value for the sample with 1% Mn and 1% La. The optical parameters of the films, such as absorption, transmittance, dielectric constants, and refractive index, were also analyzed. DSSCs were fabricated using the prepared ZnO films. For pure ZnO film, the values were: efficiency = 0.69%, current density = 2.5 mAcm-2, and open-circuit voltage = 0.56 V. When ZnO was co-doped with Mn and La, the efficiency increased significantly. DSSCs with a ZnO photoanode co-doped with 1% Mn and 1% La exhibited maximum values of Jsc = 4.28 mAcm-2, Voc = 0.6 V, and efficiency = 1.89%, which is 174% better than pristine ZnO-based DSSCs. This material is good for the electrode of perovskite solar cells.

Influence of ZnF2 and WO3 on Radiation Attenuation Features of Oxyfluoride Tellurite WO3-ZnF2-TeO2 Glasses Using Phy-X/PSD Software.

The radiation shielding features of the ternary oxyfluoride tellurite glasses were studied by calculating different shielding factors. The effect of the TeO2, WO3, and ZnF2 on the tested glass system's attenuating performance was predicted from the examination. The mass attenuation coefficient (µ/ρ) values for the oxyfluoride tellurite glasses depend highly on the concentration of WO3, as well as ZnF2. All the present ZnFWTe1-ZnFWTe5 samples have higher µ/ρ values than that of the pure TeO2 glass at all energies. For the samples with a fixed content of WO3, the replacement of TeO2 by ZnF2 increases the µ/ρ, while for the glasses with a fixed content of TeO2, the replacement of WO3 by ZnF2 results in a decline in the µ/ρ values. The results revealed that ZnFWTe4 has the lowest linear attenuation coefficient (µ) among the oxyfluoride tellurite glasses, whereby it has a slightly higher value than pure TeO2 glass. The maximum effective atomic number (Zeff) is found at 0.284 MeV and varied between 31.75 and 34.30 for the tested glasses; it equaled to 30.29 for the pure TeO2 glass. The half-value layer (HVL) of the glasses showed a gradual decline with increasing density. The pure TeO2 was revealed to have thicker HVL than the selected oxyfluoride tellurite glasses. A 1.901-cm thickness of the sample, ZnFWTe1, is required to decrease the intensity of a photon with an energy of 0.284 MeV to one-tenth of its original, whereas 1.936, 1.956, 2.212, and 2.079 cm are required for glasses ZnFWTe2, ZnFWTe3, ZnFWTe4, and ZnFWTe5, respectively.

Nonlinear Optical Limiting and Radiation Shielding Characteristics of Sm2O3 Doped Cadmium Sodium Lithium Borate Glasses.

Strong nonlinear absorption (NLA), reduced optical limiting (OL) thresholds, and high radiation shielding parameters are required for the effective use of glasses in the laser radiation and nuclear radiation protecting materials. In view of this, the efficacy of Sm2O3 on the nonlinear optical (NLO) and OL properties were ascertained (at 532 nm) along with radiation shielding characteristics. The open and closed aperture Z-scan profiles revealed the presence of positive NLA and nonlinear refraction (NLR) phenomena respectively. OL measurements showed the existence of limiting behavior in the studied glasses. The NLA and NLR coefficients were improved while the OL thresholds were decreased as the doping of Sm2O3 elevated to a higher doping level. These improvements in NLA, NLR coefficients and OL efficiencies were attributed to the non-bridging oxygens and high polarizable Sm3+ ions. The NLA and OL results clearly suggest the high (5 mol %) Sm2O3 doped glass (Sm5CNLB) glass is beneficial to protect the delicate devices and human eye by suppressing the high energy laser light. The theoretical linear attenuation coefficients (LAC) values of the presented SmxCNLB glasses were obtained with the help of Phy-X software between 0.284 and 1.333 MeV. At 0.284 MeV, the maximum values occur and take values between 0.302 (for Sm0CNLB) and 0.409 cm-1 (for Sm5CNLB). We found that the LAC for the presented SmxCNLB glasses is a function of Sm2O3 content, where the LAC tends to increase, corresponding to the high probabilities of interaction, as the content of Sm2O3 changes from 0 to 5 mol %. The effective atomic number (Zeff) for the presented SmxCNLB glasses was examined between 0.284 and 1.333 MeV. As the amount of Sm2O3 is added, the Zeff increases, and this was observed at any energy.

A New Approach to the Formation of Nanosized Gold and Beryllium Films by Ion-Beam Sputtering Deposition.

Thin films of beryllium and gold that are several tens of nanometers thick were obtained, for the first time, on silicon and quartz substrates by the ion-beam method with tenfold alternation of deposition and partial sputtering of the nanosized metal layer. Scanning electron and atomic force microscopy indicate the predominant lateral growth of nanosized metal layers along the substrate surface. Optical spectra indicate the suppression of the localized plasmon resonance. The growth of the film occurs under the influence of the high-energy component of the sputtered metal atoms' flux. The main role in the formation of the nanosized metal film is played by the processes of the elastic collision of incident metal atoms with the atoms of a substrate and a growing metal film. Metal films that are obtained by the tenfold application of the deposition-sputtering of a nanoscale metal layer are characterized by stronger adhesion to the substrate and have better morphological, electrical, and optical characteristics than those that are obtained by means of direct single deposition.