Bismuth Oxide Content Research Articles

Effect of Bismuth Oxide on the Structure, Electrical Resistance and Magnetization of Lithium Zinc Ferrite

The structural, electrical, and magnetic properties of lithium zinc ferrite prepared by ceramic technology have been studied. The composition of lithium zinc ferrite is Li0.4Fe2.4Zn0.2O4 with 1 and 2 wt % bismuth oxide. The addition of Bi2O3 prior to sintering of the samples has been shown to affect the structural, electrical, and magnetic properties of the ferrite. A significant increase in density from 4.47 to 4.65 g/cm3 and a decrease in porosity from 4.8 to 2.3% have been observed when the concentration of bismuth oxide has been increased to 2 wt %. The Bi2O3-containing samples have higher specific electrical resistivity compared to that of the additive-free lithium zinc ferrite. The introduction of bismuth oxide has reduced the specific saturation magnetization from 70.55 to 54.76 G cm3/g. The Curie temperature has not changed significantly. An optimal combination of macroscopic properties of ferrite has been found at 1 wt % Bi2O3 concentration.

High transparent glass of germanate-borate-tellurite modified by different concentration of bismuth oxide for optical and radiation shielding applications

The current investigation studied one of the high-density heavy metal oxides (Bi2O3) having density = 8.9 g/cm³, which was utilized to improve structural and optical features of the B2O3–TeO2-GeO2-MgO glass system. Three high transparent glasses with a chemical formula of 35B2O3–20TeO2-10GeO2-35MgO-xBi2O3 (x = 5, 10, and 15 mol %) were fabricated by melting at 1100 °C for 20 min and annealing at 400 °C for 5 h. X-ray diffraction measurements for the Bi5 sample, containing 5 mol % Bi2O3, were obtained at the range of 10°–80° to inspect the structural characteristics of the made glasses. Optical absorption was employed and recorded for Bi5, Bi10, and Bi15 samples at wavelength range 300–1000 nm to examine the optical properties, including optical band gap. Using Makishima and Mackenzie methods, the mechanical features of the glass samples were assessed. Nuclear library ENDF/B-VI.8 is coupled to the MCNP-5 code and is used to study and simulate the prepared Bi glass sample shielding parameters. The ionizing absorption properties for the prepared Bi5, Bi10, and Bi15 samples were found to be changed because of many circumstances like the photon energy (Eγ, MeV), and chemical compositions (Bi2O3 content (mol. %). The increased layer thickness of glass between 25 and 200 mm enhances the RPE values at 0.6 MeV over the range of 16.31–50.93 % (Bi5 glass sample), 18.68–56.26 % (Bi10 glass sample), and 20.80–60.66 % (Bi15 glass sample).

Impact of bismuth oxide on structural, optical and gamma-ray shielding properties of calcium-sodium-borate glasses.

In the present study, we have prepared six glass samples of bismuth borate using the melt-quenching method with the composition (70-x)B2O3-10CaO-20Na2O-xBi2O3; x=0, 3, 6, 9, 12 and 15mol%. The density of the prepared glasses was determined using Archimedes principle. The X-ray diffraction patterns provide confirmation of the amorphous nature of the prepared samples, whereas the Fourier transform infrared measurements pointed to the existence of structural units like BO3, BO4, BiO3 and BiO6 within the glass network. An assessment of the optical absorption spectra unveiled that with the increase in the bismuth oxide content, there was a decrease observed in both the direct and indirect band gap energies. Specifically, they decreased from 3.40 to 2.79eV and from 3.10 to 2.46eV, respectively. The properties related to gamma ray attenuation, including the mass attenuation coefficient (μm), effective atomic number (Zeff), half-value layer (HVL) and mean free path (MFP), were examined for all the glass samples. This investigation was carried out using the Phy-X/PSD software, covering the energy range from 0.511 to 1.332MeV. Out of all the samples, Bi-15, featuring the highest Bi2O3 content, demonstrated the highest μm, Zeff, the smallest HVL and MFP. These results suggest that the glass with 15mol% of Bi2O3 offers the most effective gamma radiation shielding performance. Moreover, the glasses examined in this study exhibit superior radiation shielding characteristics compared with specific concrete types, namely, ordinary concrete, Hematite serpentine concrete and barite concrete, as well as commercial glasses such as RS-360 and RS-253.

Fabrication and characterization of TeO2–Na2O–BaO glass doped with Yb2O3 for optical and particulate-radiation shielding applications: Role of Bi2O3/WO3

In this research, transparent 64TeO2–15Na2O–5BaO-(10-x)Bi2O3-(x+5)WO3-1Yb2O3 glasses were prepared and analysed for their optical, structural, and radiation protection potentials. Samples of the novel glasses were produced in the laboratory, starting with the melting-quenching process. The glasses were characterised using standard laboratory procedures and dedicated software. The influence of replacing WO3 with Bi2O3 on the investigated properties was highlighted. The values of the glass density increase from 5.42 g/cm3 to 5.67 g/cm3 as the bismuth oxide concentration increases from 0 to 10 mol%. XRD spectrograms of the glass samples reveal that they have an amorphous structure. The glasses had high optical transparency, which was reduced when WO3 was replaced by Bi. The photoluminescence decay showed that the luminescence lifetime of Yb3+ decreases with increasing bismuth concentration. For electrons, the mass stopping powers (Sp) were within 1.253–8.918 MeV cm2/g, 1.241–8.721 MeV cm2/g, and 1.232–8.549 MeV cm2/g for samples containing 0, 5, and 10 mol% of Bi2O3. Generally, Sp of electrons, protons, alpha particles, and 12C ions were in the order, (Sp)TWBi−0>(Sp)TWBi−5>(Sp)TWBi−10. Increasing the concentration of Bi atomic density in the glasses improved the total interaction probability of thermal neutrons but reduced the ability of the glasses to moderate fast neutrons.

Temperature Dependence of the Specific Heat Capacity Glasses Produced Based on Na<sub>2</sub>B<sub>4</sub>O<sub>7</sub> + Bi<sub>2</sub>O<sub>3</sub>

In this work, the temperature dependence of the specific heat capacity of glasses obtained on the basis of the Na2B4O7 + Bi2O3 compound with different concentrations of sodium tetraborate and bismuth oxide in the initial mixture was studied experimentally during cooling. It has been experimentally shown that with a change in the concentration of the initial substances, the specific heat capacity of the sample’s changes, and a shift of the maxima towards low temperatures is observed with an increase in the concentration of bismuth oxide. A physical interpretation of the nature of the maximum on the temperature dependence of the specific heat is given.

Structural and gamma-ray attenuation of mixed former lead-free borophosphate glasses

Sodium borophosphate parent glass in conjugation with other derived samples containing adaptable amounts of bismuth oxide at the expense of phosphate partner was prepared via the ordinary melt-quenching technique. Synthesized samples were investigated using Fourier transforms infrared (FTIR) spectroscopy. The undercover or overlapped peaks were estimated using the deconvolution analysis technique (DAT). The collected IR spectra refer to the presence of combined PO4 and BO3+BO4 groups besides the presence of Bi–O vibrations upon the addition of Bi2O3. The assignments of the IR peaks are facilitated by the conduction of deconvolution processes. The density of the studied glass was estimated and some selected physical parameters including molar volume and packing density were calculated.Gamma-ray shielding competence of studied borophosphate glasses has been explored through user online friendly software (Phy-X/PSD) in combination with their abilities to act as shielding candidates as a function of Bi2O3 content. In addition, linear and mass attenuation coefficients (μm) combined with other physics parameters were calculated to assess the proper action of bismuth oxide in the shielding mechanism. Sample NABP10Bi enriched with Bi2O3 possessed the highest values of LAC, MAC, and Zeff. The HVL parameter followed the trend that was considered to be dependent on the bismuth oxide concentration.

Correlation of the chemical composition, phase content, structural characteristics and magnetic properties of the Bi-substituted M-type hexaferrites

Bi-substituted M-type hexaferrites, BaFe12-xBixO19 (0.1 ≤ x ≤ 1.2), or Bi-BaM, were produced by the solid-state reactions. The correlation between the phase content, chemical composition, crystal structure features, and peculiarities of the magnetic properties of Bi-BaM was established using XRD (X-ray diffraction), SEM (scanning electron microscopy), and VSM (vibrational sample magnetometry). XRD phase analysis made it possible to establish the limit of substitution of Fe3+ ions by Bi3+ ions. It was shown that at a low substitution level (x ≤ 0.3), no impurity phases were detected, and the samples are characterized by a single-phase state with the space group (SG) P63/mmc. As the degree of substitution (x ≥ 0.6) increases, the formation of impurity phases was observed, which can be explained by the difficulties of ion diffusion in the process of solid-phase synthesis as well as the formation of defects in the magnetoplumbite structure due to the large ionic radius of Bi3+. As impurity phases in the studied compositions (x ≥ 0.6) the following were noted: BiFeO3 (SG: Pnma); BiO2 (SG: Fm-3m); BaBi2O6 (SG: R-3); and Ba0.5Bi1.5O2.16 (SG: Im-3m). The content of the main phase (SG: P63/mmc) decreases from 95.11 to 88.27 vol% with an increase in x from 0.6 to 1.2, respectively. Analysis of SEM images showed the growth of particles up to 10 μm, depending on the concentration of bismuth oxide during hexaferrite synthase. The Bi-BaM magnetic characteristics were examined using VSM in the range of 3 T at 300 K. Due to the magnetic structure's frustration, with increased x a decrease in saturation magnetization (Ms) was found. There were two concentration diapasons with different speeds of Ms decrease. In the first diapason, the main contribution belong to the magnetic structure frustration in the frame of the main phase (P63/mmc) due to the long-range Fe-O-Fe exchange interaction weakening (under Bi substitution). In the second diapason, the main contribution belong to the impurity phase formation and decrease of the main magnetic phase concentration in samples.

Hazardous radiation protective glasses for medical and research laboratories

In the current study, the bismuth oxide (Bi2O3) content was inter-substituted with gadolinium oxide (Gd2O3) in sodium borate glass. Glass sample density and molar volume values show a reverse trend. The optical transparent radiation shielding glasses are more commonly used materials in hospitals or any hazardous radiation working environments, the glasses used in this work are more emphasized on their superior transmittance and acceptable for shielding materials for commercial purposes. The optical band gap value was calculated using the Tauc plot and absorption fitting method. Radiation shielding parameters like mass attenuation co-efficient, effective atomic number, effective electron density, equivalent atomic number, lead equivalent thickness, half value layer, tenth value layer, Geometric-Progression fitting parameters like (b, c, a, XK, and d), γ-ray build-up factor, and exposure build-up factor have all been evaluated. In the current work, photoluminescence studies for Gd3+ ions were investigated and discussed.

Bismuth-Germanate Glasses: Synthesis, Structure, Luminescence, and Crystallization

Bismuth-germanate glasses, which are well known as a promising active medium for broadband near-infrared spectral range fiber lasers and as an initial matrix for nonlinear optical glass ceramics, have been synthesized in a 5–50 mol% Bi2O3 wide concentration range. Their structural and physical characteristics were studied by Raman and FT-IR spectroscopy, differential scanning calorimetry, X-ray diffraction, optical, and luminescence methods. It has been found that the main structural units of glasses are [BiO6] and [GeO4]. The growth in bismuth oxide content resulted in an increase in density and refractive index. The spectral and luminescent properties of glasses strongly depended on the amount of bismuth active centers. The maximum intensity of IR luminescence has been achieved for the 5Bi2O3-95GeO2 sample. The heat treatment of glasses resulted in the formation of several crystalline phases, the structure and amount of which depended on the initial glass composition. The main phases were non-linear Bi2GeO5 and scintillating Bi4Ge3O12. Comparing with the previous papers dealing with bismuth and germanium oxide-based glasses, we enlarge the range of Bi2O3 concentration up to 50 mol% and decrease the synthesis temperature from 1300 to 1100 °C.

Study of bismuth oxide/polystyrene composites as flexible electrodes for super capacitors

Efficient and high storage capacity composite electrodes are needed to store energy in flexible devices. We are reporting effect of filler concentration of bismuth oxide (Bi2O3) (Bi2O3 represented as BO = 1 to 5 wt%) on the charge storage performance of polystyrene (PS) composites. Bi2O3/PS composites fabricated via solution casting method, show homogenous distribution of bismuth oxide (Bi2O3) in the polystyrene matrix and attains high dielectric constant upto 5.39 at low frequency while stable dielectric constant upto 4.38 at high frequency attributes interfacial polarization occurred due to bismuth oxide distribution in the polystyrene matrix. The dielectric response indicates that Bi2O3/PS composites maybe thought of as flexible electrodes for high performance super capacitors.

Влияние замещения ионами Bi-=SUP=-3+-=/SUP=- на структурно-фазовое состояние и особенности магнитной структуры твердого раствора BaFe-=SUB=-12-x-=/SUB=-Bi-=SUB=-x-=/SUB=-O-=SUB=-19-=/SUB=-

The results of studies of the features of the phase composition, crystal and magnetic structure of Bi-substituted barium hexaferrite BaFe12-xBixO19 (0.1≤ x≤ 1.2) by methods of Mossbauer spectroscopy, X-ray phase analysis, as well as image analysis by scanning electron microscopy are presented. Samples of Bi-substituted hexaferrites - BaFe12-xBixO19 (where x=0.1; 0.3; 0.6; 0.9 and 1.2) were synthesized by the method of solid-phase reactions with double annealing (at T=1100oC for 6 h) and intermediate grinding (for 0.5 h). The X-ray phase analysis allowed us to establish the limit of substitution of Fe3+ ions by Bi3+ ions. It has been shown that at a low level of substitution (x≤0.3) there are no impurity phases detected and the samples are characterized by a single-phase state with the spatial group P63/mmc. When the degree of substitution increases (x>0.3) the formation of impurity phases is noted, which can be explained by the difficulties of ion diffusion in the process of solid-phase synthesis, as well as the formation of defects in the structure of magentoplumbite due to the large ionic radius of Bi3+. As impurity phases in the studied compositions (x>0.3) Marked: BiFeO3 (Pr. Gr. Pnma); BiO2 (Pr. Gr. Fm-3m); BaBi2O6 (Pr. Gr. R-3) and BaO0,5Bi1,5O2,16 (Pr. Gr. Im-3m). The content of the main phase (Pr. Gr. P63mmc) at the same time decreases from 95.11 to 88.27 vol.% when increasing x from 0.6 to 1.2, respectively. The analysis performed by the method of Messbaurov spectroscopy showed that all Fe ions have a charge of 3+. And all parameters lie within the values characteristic of Fe3+ ions corresponding to the coordination of polyhedra: 12k. 4f2, 2a - octahedra, 4f1 - tetrahedron, and 2b - bipyramide. It is possible to single out a small monotonous decrease only for the 12k position. The analysis of SEM images showed an increase in the average particle size up to 10 mkm, depending on the concentration of bismuth oxide during the synthesis of hexaferrite.

The dual role of bismuth in Li2O–Bi2O3–B2O3 glasses along the orthoborate join

AbstractThe structures of glasses in the lithium–bismuth orthoborate composition range deviate significantly from the short‐range order structure of the two crystalline end‐members. Although binary Li3BO3 and BiBO3 are solely of comprised trigonal orthoborate anions, all glasses formed by their combination contain four‐coordinated borate tetrahedra. We analyze the structure of (75−1.5x)Li2O–xBi2O3–(25+0.5x)B2O3 glasses in increments of x = 5, with 11B magic‐angle spinning nuclear magnetic resonance (NMR), infrared (IR), and Raman spectroscopy. For the full series, the oxygen‐to‐boron ratio remains constant at O/B = 3:1. NMR quantifies an increase in the fraction of tetrahedral boron with increasing bismuth oxide content. Evolution of the mid‐IR profile suggests multiple types of tetrahedral boron sites. Raman spectroscopy reveals that Bi2O3 tends to cluster within the lithium borate matrix when initially introduced and that this behavior transforms into a bismuthate network with increasing bismuth oxide content. In all cases, mixed Bi–O–B linkages are observed. The dual role of bismuth as network modifier and network former is likewise observed in the far IR. The glass transition temperature continuously increases with bismuth oxide content; however, the glass stability displays a maximum in the multicomponent glass of x = 40.

Influence of excess bismuth oxide on the structural and dielectric characteristics of textured Bi4Ti3O12 ceramics

Bismuth titanate (Bi4Ti3O12), an Aurivillius family of ferroelectric oxide, has been widely investigated due to its large remnant polarization, high Curie temperature, high dielectric constant and relatively low tangent for the application in information memory storage devices. In this work, polycrystalline bismuth titanate ceramics samples with different amounts of excess Bi2O3 (3 and 5 wt%) were prepared using a low temperature, cost-effective molten salt synthesis method. The structural, microstructural and dielectric properties depend on the addition of excess Bi2O3 and the sintering duration of Bi4Ti3O12 ceramics. Moreover, the X-ray diffraction studies revealed the effect of excess bismuth oxide on the formation of preferential orientation along the c-axis. It is also observed that the orientation factor along the c-axis increases with an increase in the sintering duration for different content of bismuth oxide. The morphological studies revealed the oriented plate-like structure of bismuth titanate ceramics associated with the enhanced growth of grains. It is noticed from the EDAX analysis that the addition of excess bismuth oxide compensated the volatilization of bismuth ions in the crystal lattice of Bi4Ti3O12 ceramics. The dielectric property studies have exhibited a high value of dielectric constant (εr ~ 190), and low tangent loss factor (tanδ ~ 0.08) for the optimum bismuth oxide content of 5 wt% added Bi4Ti3O12 ceramics. Hence, we suggest that these materials could be utilized for the high energy storage capacity of non-volatile memory devices.

Physical, structural and spectroscopic studies of Al2O3-B2O3-Sm2O3 scintillating glass doped with heavy metal oxides

In the present paper, physical, structural, optical and luminescence properties of Sm3+ activated scintillating glasses with variation in Bi2O3 concentration have been studied. The amorphous nature of the glass samples was ascertained by the presence of a broad hump in XRD spectra. FTIR examinations advocated that Bi2O3 exists primarily as [BiO6] units and BO4 units enhanced with surging bismuth oxide content. The values of density increase continuously with the addition of Bi2O3, whereas Vm first decreases till 25 mol% Bi2O3 content, after that it is found to increase. Optical characterization of samples affirms strong sensitivity towards the absorbance of UV–visible radiation. Among the prepared samples, 35 mol% of Bi2O3 doped glass showed the lowest bandgap, high refractive index and Urbach energy. Also, it contains more localized states that confirm its suitability as a protection material from UV radiation. PL results reveal the strong emission occurs at 562, 598, 644, 704 nm wavelength and Bi15 glass exhibits maximum intensity in both excitation and emission spectrum. The intense emission peak originated from 4G5/2 → 6H7/2 transition centered at 600 nm in XRL which discloses the scintillation properties of the material. The CIE chromaticity diagram demonstrated the emission located in the reddish-orange region, which suggests prepared glasses could be useful for reddish-orange laser and LED. Thus, 15 mol% Bi2O3 doped glass becomes more efficient for the use of scintillators in high-energy physics experiments.

Effect of Bi2O3 contents on magnetic and electromagnetic properties of LiZnMn ferrite ceramics

Soft LiZnMn ferrites with low coercive force values and small grain sizes were developed by the solution combustion synthesis and low temperature sintering technique for microwave applications at a high frequencies. Bismuth oxide was used as an additive to lower the sintering temperature. The examination covered the influence of Bi2O3 on the crystal structure, microstructure, primary magnetic and dielectric characteristics of lithium-zinc-manganese ferrites. The most promising sample designed for using in microwave devices was produced by sintering at 1075 ℃ temperature for 8 h with added 1.5 wt% Bi2O3. These production conditions have yielded 2.98 µm average grain size in a ceramic product, the density is 4.84 cu cm/g, and the coercive force, residual induction, and saturation induction are 58 A/m, 2078.4 G, and 3439.1 G, respectively. In addition, this sample demonstrates a high initial magnetic permeability (μi = 168), Curie temperature (Tc = 437.5 ℃), high values of the dielectric loss tangent (tan δɛ = 6.32⸱10−3), ferromagnetic resonance line width (ΔH = 280 Oe) and the resonance line of spin waves (ΔHk = 1.87 Oe). Further increase in the bismuth oxide content allows observing a change in the ceramics microstructure, accompanied by a deterioration in the magnetic and electromagnetic characteristics. Here, the discussion covers the mechanism of change in the functional properties of lithium-zinc-manganese ferrites produced in the conditions of solution combustion with added bismuth oxide. Thus, synthesizing of initial pre-ceramic powder by glycine-nitrate combustion and subsequent low-temperature sintering with added bismuth oxide is a novel efficient technique of producing advanced soft high-frequency LiZnMn ferrites.

Fused filament fabrication of complex anatomical phantoms with infill-tunable image contrast

Fused filament fabrication (FFF) provides a rapid means of producing anatomical models for biomedical education and training. However, FFF-compatible materials and methods are currently limited for efficient and accurate production of complex phantoms that can mimic the radiological properties of multiple human tissues. It is demonstrated in this research that the computed tomography (CT) contrast can be modified by varying the concentration of bismuth oxide in acrylonitrile butadiene styrene (ABS) filaments and by modifying the infill percentage of the printed models. By using an infill geometry consisting of an encapsulated pore structure, the CT contrast of fat, blood, kidney, liver, trabecular bone, and cortical bone could be successfully displayed without the presence of any artificial artefacts in the images. In addition, a lumbar spine phantom is printed with the infill varied throughout the model to accurately mimic the CT contrast for the trabecular and cortical bone volumes. This research is of particular relevance for FFF-printing of anatomical models for radiology education and image-guided surgical training.

Recycling and optimizing waste lab glass with Bi2O3 nanoparticles to use as a transparent shield for photons

This study aims to experimentally analyze the radiation shielding capabilities of micro and nano bismuth oxide waste glasses by evaluating the effect of particle size, bismuth oxide content, and energy on the attenuation abilities of the samples. Waste glasses were powdered and combined with varying amounts of bismuth oxide with different particle sizes to test a total of seven waste glasses using the collimate gamma-ray technique. Energy dispersive X-ray analysis and a scanning electron microscope were used to determine the homogeneity of the samples. The experimental mass attenuation coefficient for the micro Bi2O3 samples was compared with values obtained from the XCOM program to determine their accuracy. From these values, the linear attenuation factor and the radiation protection efficiency of the waste glass samples were obtained. The results demonstrated that the smaller particle size of the glasses with nanoparticles led to an enhancement in their radiation shielding properties compared to the samples with microparticles. This improvement occurs because of the greater homogeneity provided by the smaller particles, allowing for more interactions between the glasses and the incoming radiation, leading to greater attenuation. The pure glass sample has a radiation protection efficiency (RPE) of 45.29% at 0.06 MeV, while the samples with Bi2O3 have RPE values ranging from 83.85 to 99.73%. The RPE for the sample with 30 w.t% micro Bi2O3 is equal to 39.43% at 0.356 MeV while the sample with 30 w.t% nano Bi2O3 is equal to 44.44%. Thus, it was concluded that the nano bismuth oxide samples are more effective at shielding gamma-rays than the micro bismuth oxide waste glasses.

Structural, dielectric and optical properties of Ta2O5-Bi2O3-P2O5phosphate glasses

Glasses with the formula 5Ta2O5-xBi2O3-(95-x)P2O5for 10 ≤x≤ 20 mol% were prepared using the standard melt-quench method and identified using X-ray diffraction, Differential Scattering Calorimetry, and Infrared spectroscopy. Furthermore, the dielectric and optical characteristics were determined. The glass transition temperature (Tg) increases linearly with bismuth oxide content, from 524 °C forx= 10 mol% to 582 °C forx= 20 mol%. When the amount of Bi2O3in the system increases, the density rises and the molar volume (VM) decreases. The Infrared spectroscopy shows the presence of BiO6and PO3structural groups and reveals the depolymerization of the phosphate links by the creation of the Bi–O–P groups. Replacing P2O5by Bi2O3shows that the dielectric constantɛr' and dielectric losses tanδvary with the concentration of added Bi2O3. Optical characteristics of the investigated glasses were determined using UV–vis spectroscopy and the energy band gap has been estimated.

Impact of Bi2O3 on optical properties and radiation attenuation characteristics of Bi2O3-Li2O-P2O5 glasses

The physical, optical, and gamma ray shielding behavior of the four Bi2O3-Li2O-P2O5 glasses with varying Li2O and Bi2O3 compositions have been explored. The glass density increases from 2.44 to 3.85 g cm-3 with bismuth oxide content. The molar volume follows the same trend as density and the overall molar volume of these glasses increases, which in turn directly affects the oxygen packing density (OPD). Optical band gap energies decrease after lithium oxide is replaced with bismuth oxide. The values of M lie between 0.3485 and 0.3209 indicates that glasses under investigation are non-metallic. Radiation shielding evaluation using EpiXS software and Phy-X/PSD program shows comparable mass attenuation coefficients (MACs) but with relatively higher percent differences at energies near the K-edge energies of O (0.538 keV) and Bi (90.5 keV). The MACs of the glasses rise when Li2O oxide is replaced with Bi2O3 oxide. The half-value layer (HVL) results showed the difference in the radiation shielding capabilities of the four glasses is more apparent at high energies. An increase in MAC and a decrease in HVL imply that adding Bi2O3 to the glass improves its radiation attenuation properties.

ПОВЫШЕНИЕ ДОЛГОВЕЧНОСТИ ЗАЩИТНЫХ ПОКРЫТИЙ МАШИН И ОБОРУДОВАНИЯ АПК НАНО МОДИФИЦИРОВАННЫМИ ЛАКОКРАСОЧНЫМИ МАТЕРИАЛАМИ

This paper discusses the current areas of work to en-sure the performance of protective coatings for machinery and equipment in theagricultural industry complex for the conditions of Siberia. The following five main areas were identified: corrosion protection, thermoregulation, fire re-sistance, antistatics and radiation protection. It was found that the most efficient way to ensure the performance of coatings is their nanomodification. The method of fire re-sistance tests developed at the Novosibirsk State Agricul-tural University is presented. The results of preliminary tests in two areas are presented: fire resistance and corro-sion protection. One of the promising nano-additives is bismuth oxide which may improve fire resistance and phys-ical and mechanical properties. According to the research results, when the concentration of bismuth oxide reaches 5%, an extremum is observed for the values of hardness (86-94) and adhesion (3.3-3.6 MPa) of the coating. At the same time, the addition of bismuth oxide in a concentration of 7.5% made it possible to achieve a significant increase in the fire resistance of the coating. Fire resistance and ignition time increased to 240°C and 65 s, respectively. Some of the most effective additives are identified and the further direction of the study is indicated which consists in optimizing the compositions of protective coatings and providing a set of properties for operating conditions in each specific case. It is also necessary to take into account the combined effect of nanomodifiers on the properties of the protective coating.