Concentrations Of Bi2O3 Research Articles

Synthesis of transparent binary germanate glasses and determination of their shielding performance against the gamma radiation

ABSTRACT In this study, we synthesized binary germanate glasses with compositions of GeO2 – Bi2O3, GeO2 – PbF2, and GeO2 – V2O5. The traditional melt-quenching method was used for glass synthesis. The radiation shielding properties of the synthesized samples were calculated theoretically and measured experimentally as well. A narrow-beam transmission geometry, which uses a NaI(Tl) detector, was employed to measure linear attenuation coefficient, mass attenuation coefficient, half-value layer, and effective atomic number values of the glasses at gamma-ray energies of 662, 1173, and 1332 keV and, 137Cs, and 60Co radioactive point sources were used to produce gamma-ray photons of these energies. Additionally, all the above parameters were also calculated theoretically using the WinXCOM software in the 0.015-15 MeV energy range to confirm the accuracy of the measurements. A good agreement between theoretical and experimental findings was observed. It was also found that the increase in the concentrations of Bi2O3, PbF2, and V2O5 network modifiers improved the radiation shielding capacity of synthesized germanate glasses. The results revealed that the GeBi30 glass has superior shielding properties among the synthesized germanate glasses.

Simulation of the impact of Bi2O3 on the performance of gamma-ray protection for lithium zinc silicate glasses

In order to enhance the radiation shielding properties for the lithium zinc silicate glasses and become suitable for gamma-ray protection applications, a partial replacement for the silicon oxide by bismuth oxide was performed. The Monte Carlo (MC) simulation was applied to evaluate the shielding capacity of the investigated glasses. The results recorded by the MC code showed that the replacement of the SiO2 by Bi2O3 causes a significant increase in the investigated glasses shielding capacity. It is varied from 46.732% to 104.207% for the samples containing 20 and 40 mol% of Bi2O3 concentrations compared to the sample containing only 10 mol% of the Bi2O3 at low gamma-photon energy of 0.224 MeV. Moreover, the highest µ values in the present study were received by the glass sample containing 40 mo% of Bi2O3 where the µ varied between 2.700 and 0.216 cm−1 when the applied gamma photon energy increased from 0.244 to 2.506 MeV.

Enhancement in the long-term stability of ZnO varistor ceramics against DC aging by controlling intergranular phases

Herein, to enhance the long-term stability, ZnO varistor ceramics mixed with Bi2O3, Sb2O3, MnCO3, Co2O3, SiO2, and different concentrations of NiO (with 0, 0.3, 0.7, 1, 1.3, 1.6 mol%) were grown for controlling the Bi2O3 intergranular phase as α-Bi2O3 using a well-known ceramic process technology. The microstructure and crystalline phases were investigated using scanning electron microscopy (SEM), X-ray energy dispersive spectrometry (EDS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The electrical properties were evaluated using a high-voltage DC power supply, current pulse generator, oscilloscope, and impedance analyzer. Results from XRD patterns and TEM indicated that the NiO dopant enables the transition of δ- to α-Bi2O3 phase. Current density-electric field measurements revealed that NiO-doped ZnO ceramics have an increased breakdown field and decreased leakage current density. During DC aging, the power loss-aging time curves of NiO-doped ZnO ceramics with increased α-Bi2O3 phase showed a downward trend, indicating increased stability. The current research has revealed that improving the electrical stability of polycrystalline ceramics via intergranular phase control might be feasible for the emerging DC power-based aging applications.

Effect of Bi2O3 and Ho2O3 co-doping on the dielectric properties and temperature reliability of X8R BaTiO3-based ceramics

Bi2O3 and Ho2O3 co-doped BaTiO3 (BT)-based X8R ceramics were successfully synthesized by the conventional solid-state reaction route. The synergistic effects of Bi3+ and Ho3+ co-doping on the dielectric performance and microstructures of BT-based ceramics were studied. The results show that by carefully adjusting the Bi2O3 and Ho2O3 doping concentrations, the temperature stability of the dielectric permittivity in BT-based ceramics can be significantly improved. Co-doped samples with 0.75%–1.5 mol% Bi2O3 and Ho2O3 meet the X8R specification. In particular, the 0.75 mol% Bi2O3 and 0.75 mol% Ho2O3 co-doped BT-based ceramics exhibit an optimum dielectric permittivity and a satisfactory temperature coefficient of capacitance (TCC) stability: the dielectric permittivity and dielectric losses are 2668 and 1.35% respectively at room temperature, the TCC at −55 °C and 150 °C is −0.92% and −9.56%, respectively. Transmission electron microscopy (TEM) analysis confirmed the formation of a core-shell microstructure in Bi2O3 and Ho2O3 co-doped BT-based ceramics. The synergistic effect of Bi3+ and Ho3+ co-doping plays a vital role in the production of the core–shell microstructure, which in turn is the main reason for the effective improvement of the TCC stability of BT-based ceramics.

Evaluation of optical, and radiation shielding features of New phosphate-based glass system

The present investigation aims to fabricate and report the optical, and radiation shielding features of a novel phosphate-based glasses. The composition of the glasses described by the equation xBi2O3+20CaO+10K2O+(30-x)Na2O+40P2O5, x=0, 2.5, 5, 7.5, and 10 mol%. The density of the fabricated samples was found in the range of 2.333 to 3.518 g/cm3. The theoretical calculations were used to calculate some physical properties like ionic concentration, the volume of phosphorus atoms, average phosphorous-phosphorus separation, polaron radius, and inter-nuclear distance. Moreover, the UV-Vis spectra were recorded using the spectrophotometer in a wavelength range between 200 and 1100 nm. The refractive index increased from 2.405 to 2.455, the dielectric constant increased from 5.784 to 6.029, while the direct band-gap decreased from 3.633 to 3.517 eV. The gamma-ray shielding characteristics were evaluated using the monte Carlo simulation in the energy interval between 0.276 and 1.458 MeV. The highest LAC achieved at 0.276 MeV and is enhanced from 0.2565 to 0.80625 cm-1, raising the Bi2O3 concentrations between 0 and 10 mol%, respectively.

Development of bismuth alumino borosilicate glass for radiation shielding material

The glass specimens in the composition of xBi2O3: 20SiO2: 20ZnO: 5Al2O3: (55-x)B2O3, where x = 10, 15, 20, 25 mol% were investigated the radiation shielding properties. The specimens were melted entirely by using the melt-quenching technique at 1200 °C. The WinXCom program has been used to compute the mass attenuation coefficient (MAC) in theoretical values. The effective atomic number (Zeff), the effective electron density (Neff), and half-value layers (HVL), tenth-value layers (TVL) and buildup factor obtained by calculations were taken into the function of the MAC. The gamma-ray transmission technique was used to measure the MAC in the energy range from 0.223 MeV to 0.662 MeV by using the Compton scattering technique for various energies from the Cs-137 source. The results showed that the experimental values have been agreed with the theoretical values. The density result was found to increase with the increasing of Bi2O3 concentrations. The MAC, effective atomic number and effective electron density had similar trends increasing when Bi2O3 concentration increased and decreasing when the energy increased. The HVL & TVL decreased with increasing of Bi2O3 contents. The HVL & TVL of the specimens were lower than that of the standard shielding materials. The energy absorption buildup factor (EABF) and exposure buildup factor (EAF) also calculate in 0.015–15 MeV.

Gamma-ray shielding studies on borate glasses containing BaO, Bi2O3, and PbO in different concentrations

Mass attenuation coefficients (μm), half value layer (HVL), effective atomic cross sections (σa), effective atomic numbers (Zeff) and effective electron densities (Neff) of borate glasses containing different concentrations of BaO, Bi2O3, and PbO (20–50% by mole) were obtained in the energy range of 10 keV–10 MeV using MCNPX code, XCOM and XMuDat programs, Auto-Zeff software and linear interpolation method. The simulated and calculated results were in good agreement with the experimental data with differences of ≤ ± 11%. It was found that σa and Zeff of glass samples improve by increasing their BaO, PbO and Bi2O3 contents, while increasing these contents to the same fraction has no significant effect on μm values in the energy range of 0.3–6 MeV, where the Compton Effect takes over as dominant process. In addition, the μm and σa values of glasses decreased with photon energy and bismuth oxide borate glass obtained the highest values of μm and σa. Also, HVL values of the studied glasses decreased with the increase in their densities. The 50Bi2O3:50B2O3 glass system had the highest Zeff value of 55.60 at the 30 keV photon energy. Above 0.4 MeV photon energy, Neff values were independent of the metal oxides contents. The Neff values of the studied glass systems varied in the range of 2.77 × 1023 – 9.10 × 1023 electron/g.

Development of bismuth sodium borate glasses for radiation shielding material

Abstract Glass samples of the bismuth sodium borate (where x = 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 mol%) have been prepared in laboratory by melt quenching technique. The radiation shielding properties including the mass attenuation coefficient, the effective atomic number, the effective electron density and the half value layer (HVL) of glass samples have been measured by using the gamma ray from radioactive source Ba-133, Na-22, Cs-137 and Co-60 at the energies 356, 511, 662, 1173 and 1332 keV for these experiment and those were compared with theoretical approach by WinXCom program. The results found that, the mass attenuation coefficient, effective atomic number, and effective electron density were increased with the increase of Bi2O3 concentrations, and those values were decreased with the increasing of gamma-ray energies. The glasses in this work showed good radiation shielding properties by providing less the HVL than some standard shielding materials at 662 keV of gamma ray

Multi-objective optimization strategies for radiation shielding performance of BZBB glasses using Bi2O3: A FLUKA Monte Carlo code calculations

Highly efficient gamma shielding of BZBB glasses with various Bi2O3 concentrations in the xBi2O3-30B2O3-(65-x)ZnO-5BaO, (5 ≤ x ≤ 25 mol%) were evaluated for their radiation shielding properties. The μm results have been evaluated via the NISTXCOM database and simulated via FLUKA code. The simulation values by Monte Carlo code (FLUKA) have been shown to converge and correlate with XCOM values. Shielding properties like HVL, MFP, Zeff, EBF, and EABF values have been computed. The values observed that μm and Zeff increase with increasing Bi2O3. 47.09, 48.91, 50.73, 52.54 and 54.36 (cm2/g) are the μm values for BZBB1, BZBB2, BZBB3, BZBB4 and BZBB5 glasses at 15 keV. Also, the μm values decrease with increasing photon energy for all glass samples. Moreover, BZBB5 sample had the lowest HVL, MFP, EBF, and EABF values. That indicates to the addition of Bi2O3 improves the radiation shielding properties of BZBB glasses. The obtained results were compared with the most commonly shielding materials such as lead and concretes. It was concluded that the improved BZBB glasses with the addition of Bi2O3 showed excellent shielding properties comparing with shielding materials. These results could be highly beneficial for fields such as medical treatment facilities.

Gamma-ray shielding properties of phosphate glasses containing Bi2O3, PbO, and BaO in different rates

Glass-based materials are one of the most common shielding materials. Phosphate glasses have unique properties that make them useful for some technical and industrial applications. The mass attenuation coefficients (μm), effective atomic cross sections (σa), effective atomic numbers and electron densities (Zeff and Neff) of phosphate glasses containing different concentrations of Bi2O3, PbO, and BaO (30–70% by weight) have been determined in the energy range of 10 keV–10 MeV. To calculate these parameters, XCOM and XMuDat computer programs and also the Auto-Zeff software and interpolation method have been used. The results of XCOM, XMuDat and Auto-Zeff programs were in good agreement. It was found that the μm and σa parameters decrease as the photon energy increase. Also, the σa and Zeff values improve by increasing the Bi2O3, PbO and BaO contents, while increasing these contents to the same fraction has no significant effect on μm in the energy range of 0.4–4 MeV, where the Compton Effect takes over as dominant process. Furthermore, the Neff is approximately independent of metal oxides concentrations. Wherever possible, the calculated values were compared with the experimental data.

Comparison of Magnetic Properties of Low-Temperature-Fired NiCuZn Ferrites Under Low- and High-Bi2O3 Doping Modes

Phase composition, microstructure and magnetic properties of the low-temperature-fired NiCuZn ferrites doped with different concentrations of Bi2O3 were investigated. A proper content of Bi2O3 doping could trigger the formation of a dual microstructure of the ferrites. The before and after ‘critical’ doping content, i.e. low- and high-Bi2O3-doping modes,enabled the ferrites to obtain sufficiently high density and equal permeability. The former sample obtained a uniform, dense and fine-grain-sized microstructure, which was beneficial to improve the high-frequency characteristic and Q-factor characteristic of the low-temperature-fired NiCuZn ferrite; moreover, the saturation flux density was higher. However, the latter sample obtained a uniform, dense and large-grain-sized microstructure with more grain-boundary-dopant, which was beneficial to improve the DC-bias superposition characteristic of the ferrite. These comparative results can essentially guide the engineering applications of the low-temperature-fired NiCuZn ferrites.

Mechanical and radiation shielding properties of flexible material based on natural rubber/ Bi2O3 composites

The purpose of this investigation have been developed lead-free and flexible radiation shielding materials. Composites of natural rubber (NR) were prepared by incorporating bismuth oxide (Bi2O3) with various loading levels. The variation mechanical properties of the composite with different loading levels have been studied. The gamma ray shielding properties were measured with 137Cs (662 keV) source by Compton scattering technique. The X-ray shielding characterization were measured with high frequency digital radiography X-ray machine Shimadzu model RAD Speed Pro. The results show that addition of Bi2O3 into natural rubber enhances the modulus at 100% elongation, hardness and specific gravity of the composites, whereas tensile strength and elongation at break reduces. For gamma ray shielding properties, the experimental values of mass attenuation coefficients (μm), effective atomic number(Zeff), effective electron densities (Ne) and lead equivalent of the NR composites were found to increase with the increasing of Bi2O3 concentrations, while these value were decrease with the increasing of photon energy from 223 keV to 662 keV. The half value layer (HVL) values of all samples were decreased with the increasing of Bi2O3 concentrations. The NR of 150 phr Bi2O3 composites found to be the lowest HVL values in comparison with commercial window, serpentine, ordinary concrete and hemimatite-serpentine. For X-ray shielding properties, the linear attenuation coefficient (μ) and lead equivalent (dPb) were increased with increased Bi2O3 add in NR and show the decreasing of X-ray energies range.

Analysis of borosilicate glasses doped with heavy metal oxides for gamma radiation shielding application using Geant4 simulation code

The goal of this research is to investigate the influence of three heavy metal oxides (Bi2O3, BaO and TiO2) on the gamma rays shielding effectiveness of borosilicate glasses. The Geant4 simulation code has been applied to estimate the mass attenuation coefficients (μ/ρ) of 30B2O3–(70-x)SiO2–xHMO glass systems (where HMO are Bi2O3, BaO and TiO2 with 0, 1, 2, 3, 4 and 5 mol%). We estimated the μ/ρ values at six energies (i.e. 0.347, 0.511, 0.826, 1.173, 1.275 and 2.506 MeV). To determine the accuracy of the obtained results, we compared the Geant4 data with those calculated using WinXcom software. The obtained Geant4 values of the selected borosilicate glasses with different concentrations of Bi2O3, BaO and TiO2 agreed quite well with the WinXcom results at all energies. The addition of Bi2O3 and BaO increases the μ/ρ values, while the samples doped with TiO2 showed insignificant changes in μ/ρ values with the addition of TiO2. All the presented samples have lower HVL than the undoped glass sample (70SiO2-30B2O3 sample). This means that the addition of the three dopants (Bi2O3, BaO and TiO2) have led to a decrease in the HVL which enhances the attenuation performance of the current samples.

Investigation of the optical properties of borosilicate glass recycled from high-pressure sodium lamp glass: Compositional dependence by addition of Bi2O3

We examined the effects of bismuth (III) oxide (Bi2O3) on the optical properties of glass. The glass samples were prepared with high-pressure sodium lamp glass as the initial material with different concentrations of Bi2O3. Optical properties such as the refractive index, optical band gap, Urbach energy, polarisability and metallisation were investigated. The results indicated that addition of Bi2O3 into the network structures of the glass samples increased the formation of non-bridging oxygen atoms. This resulted in a decrease of the optical band gap and an increase in the polarisability of the glass samples. The types of electron transitions were studied by comparison between the differential method and the Davis and Mott model. The results showed that the electrons moved directly by an allowed transition.

Facile synthesis of sodium bismuthate dihydrate and its efficient visible-light photocatalytic activity

A novel, green approach for the synthesis of sodium bismuthate dihydrate (NaBiO3·2H2O) was reported for the first time by using sodium persulfate (Na2S2O8) as an oxidant. Compared with traditional synthetic approach exhausting poisonous gas inevitably, the approach in this paper is easier, safer and more expedient. The as-fabricated samples were characterized by some techniques, such as X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Uv–vis diffuse reflectance spectrum (DRS). The effects of reaction conditions were also investigated and discussed in detail. Under the same conditions (oil bath time and temperature), low concentrations of alkali lead to formation of cubic Bi2O3 and higher concentrations resulted in formation of NaBiO3·2H2O. Well-crystallized monophase NaBiO3·2H2O was obtained at 90 °C, while a mixture of NaBiO3·xH2O and NaBiO3·2H2O was obtained at 50 °C with the base concentration of 10 mol L−1. In comparison with the samples containing NaBiO3·xH2O, monophase NaBiO3·2H2O with well crystallinity shows superior photocatalytic performance for the degradation of Rhodamine B under visible-light irradiation.

Dielectric and spectroscopic investigations on zinc arsenate glasses with Bi2O3 as additive

Abstract (50-X) ZnO-50 As2O3-X Bi2O3 (5 ≤ X ≤ 30 with the increment of 5 mol %) glasses were synthesized by melt quenching with subsequent annealing. The prepared glasses were characterized by X-ray diffraction, which confirmed the glassy nature of the samples. Spectroscopic studies viz., optical absorption, FTIR and dielectric studies were carried out. Optical absorption spectra revealed the progressive increase of NBO is with the increase of Bi2O3 concentration. From FTIR spectra it is evident that at lower concentrations of Bi2O3 Bi3+ ions enter into the glass network by forming BiO3 pyramidal structures in conjunction with tetrahedral ZnO4 where as octahedral BiO6 structural units predominate with the increase of Bi2O3 content. The dielectric parameters like e′, tan δ and σac are found to increase with the increase of Bi2O3 concentration while a fall of activation energy for conduction is noticed. The correlation between the above said studies suggests that the glasses are more rigid at lower concentrations of Bi2O3 and conductivity of the glasses is observed to increase at higher concentrations of Bi2O3 due to increase of BiO6 and ZnO6 structural units. Hence, C1 sample (45 ZnO-50 As2O3- 5 Bi2O3) is found more rigid and highly insulating glass.

Gamma-ray shielding properties for silicate glasses containing Bi2O3, PbO, and BaO

Introduction: With the extensive application of radiation sources and radioactive materials in various fields, the study of attenuation and absorption of X-rays and gamma-rays in several materials has become an essential and interesting field of research. Glass materials are possible alternatives of concretes for radiation-shielding materials. Materials and Methods: The mass attenuation coefficients (µm), effective atomic cross section (σa), effective atomic number (Zeff) and effective electron density (Neff) of silicate glasses containing different concentrations of Bi2O3, PbO, and BaO (30–70% by weight) were obtained using MCNP-4C code, XCOM and XMuDat programs, in the energy range of 10 keV–10 MeV. The interpolation method was employed to extract Zeff and Neff. The Auto-Zeff software was used to determine the Zeff as well. Results: The MCNP-4C Code, XCOM and XMuDat programs and Auto-Zeff results were in good agreement. It was found that the µm and σa values decrease with photon energy. Also the results indicate that σa and Zeff of glasses improve by increasing their Bi2O3, PbO and BaO contents, while increasing these contents to the same fraction has no significant effect on µm in the energy range of 0.3–5 MeV, where the Compton Effect takes over as dominant process and Neff do not follow certain rule. Above 0.1 MeV, lead oxide silicate glass showed the highest values of Zeff and σa. Conclusion: Observed good agreement indicates that the chosen Monte Carlo code and computer programs may be useful to calculate the gamma-ray shielding characteristics of different glass systems, particularly in cases where no experimental data exist.

Effects of calcination temperature and flux doping on the microstructure and magnetic properties of low-temperature-fired NiCuZn ferrites

The correlative influences of calcination temperature and Bi2O3 doping content on the microstructure and magnetic properties of the low-temperature-fired NiCuZn ferrites were investigated. For ferrites with relatively low calcination temperatures, such as 750 °C and 850 °C, Bi2O3 doping easily triggered inhomogeneous grain growth. Controlling the flux amount to lower than the ‘critical’ value, which triggered abnormal grain growth, was preferred to obtain good magnetic properties. For ferrites with relatively high calcination temperatures, such as 950 °C and 1050 °C, flux doping was not prone to stimulating abnormal grain growth. Thus, the optimum doping content could be added when the highest sintered density was detected. With excessive Bi2O3 concentrations, low-temperature-calcined ferrites could produce homogeneous microstructures with a relatively large average grain size. By contrast, high-temperature-calcined ferrites could form homogeneous microstructures with a relatively small average size, which favoured a high Q-factor and was more favourable for high frequency applications.

Physical properties of B2O3–TeO2–Bi2O3 glass system

Boro-tellurite glass system with different concentrations of Bi2O3 had been prepared and characterized. The FTIR analysis indicated a glass former role of Bi2O3 that was deduced from the formation of [BiO3] structural units. These units transformed the structural units [TeO3] into [TeO4] and [BO3] into [BO4]. This process increased the environment of bridging oxygens that increased the density and decreased the molar volume of the glass structure. The increase of the ultrasonic velocities, the elastic moduli (experimentally determined and theoretically computed according to Makishima-Mackenzie model) with the addition of Bi2O3 was attributed to the increased compactness and rigidity. The increment coordination number increased the cross-link density and improved the glass transition temperature. The hyper-polarizability of Bi3+ due to the d-orbital contribution increased the crystallization peak and enhanced the thermal stability.

Chemically synthesized ZnO-Bi2O3 (BZO) nanocomposites with tunable optical, photoluminescence and antibacterial characteristics

This study unravels the soft chemical synthesis of Bi2O3/ZnO (BZO) nanocomposites having nano-cones like morphology with tunable optical and luminescent properties. The prepared BZO samples with varying Bi2O3 concentrations have been characterized for structural, morphological, band gap energy, photoluminescence (PL) and antibacterial characteristics. Structural and morphological investigations revealed the separate single wurtzite phase of ZnO and monoclinic phase of Bi2O3 without any undesired phases with dominant nano-cones like morphology. Optical and PL analysis have depicted the band gap widening, enhanced ultra-violet (UV) emission and decreased defects densities of BZO nanocomposites as compared to pristine ZnO nano-cones. Interestingly, a good correlation between defects and antibacterial activity of ZnO nanostructures has been found.