Sb2O3 System Research Articles

Bismuth(III) oxide and boron(III) oxide substitution in bismuth-boro-zinc glasses: A focusing in nuclear radiation shielding properties

Doping the glass structure with Bi2O3 `is known to increase structural stability, and to drastically alter physical parameters including density and molar volume. The goal of this work was to assess the nuclear radiation attenuation competences of several types of glasses based on the xBi2O3-(70-x)B2O3-8BaO-16ZnO-5.5SiO2- 0.5Sb2O3 system. In order to determine the requisite gamma shielding parameters, as well as effective conductivity at 300 K and buildup factors, five different glasses with varied Bi2O3 concentration (i.e., from 10 mol.% to 30 mol.%) were examined thoroughly. These critical parameters were determined using the Phy-X/PSD program. In addition, factors such as half value layer (HVL), tenth value layer (TVL), and mean free path (mfp) were examined over a wide energy range of 0.015–15 MeV. The findings revealed that the amount of Bi2O3 reinforced in each sample is critical in determining the samples' shielding abilities. The linear attenuation coefficients (µ) and mass attenuation coefficient (µm) values were reported in the highest level for the sample with the highest Bi2O3 content. For glass sample A5, the lowest mean free path, half value layer, and tenth value layer values were also reported. The effective conductivity and effective atomic number had an inverse relationship with photon energy, meaning that as energy increased, the effective conductivity and effective atomic number declined fast, especially in low-energy regions. The greatest values for both parameters were found in glass sample A5. Furthermore, the exposure buildup factor and energy absorption buildup factor values for glass sample A5 were the lowest. A5 glass sample with the chemical composition 30Bi2O3-(70−30) B2O3-8BaO-16ZnO-5.5SiO2- 0.5Sb2O3 and a density of 5.8391 g/cm3 was found to have exceptional gamma-ray attenuation qualities, according to our findings. It can be concluded that the prospective attributes of Bi2O3-doped glass systems and associated glass compositions would be beneficial for scientific community in terms of providing a clearer view for some advanced applications of these glass types.

Physical, structural, optical, and radiation shielding properties of B2O3- 20Bi2O3- 20Na2O2- Sb2O3 glasses: Role of Sb2O3

This paper focuses on the role of antimony oxide (up to 15 wt%) in the physical, structural, optical, and radiation attenuating characteristics of boro-bismuth glasses within B2O3-20Bi2O3- 20Na2O2- Sb2O3 system. This glass system was prepared by melting at 1250°C and quenching into water. The physical properties were studied by measuring the density, molar volume, and x-ray diffraction for the prepared glass system. The structural features were investigated by determining packing density, passion ratio, oxygen packing density, and oxygen molar volume. The optical attributes were explored by evaluating bandgap, Urbach energy, refractive index, and other related parameters such as dielectric constant, reflection loss, molar polarizability, molar refractivity, optical dielectric constant, optical electronegativity, electron polarizability, optical basicity, metallization, and cut-off wavelength. On the other hand, the shielding properties of the prepared glasses were studied against different types of radiation such as gamma, electron, proton, and neutron beams. The radiation studies were carried out by utilizing Geant4 simulations and the newly developed Phy-X/PSD program. The radiation-shielding characteristics of the present samples were examined in terms of mass attenuation coefficient, stopping power, half value layer, removal cross section, mean free path, and effective atomic number of gamma, electron, and proton beams. The results showed that antimony oxide content had an important influence on the shielding ability against all of the types of radiations. Additionally, the obtained results were compared with those of standard radiation shields. It can be concluded that the present glasses have a promising future to be used as radiation shielding material, wherein the antimony oxide concentration can be balanced according to the desired application.

Measurement and Modelling of Pyrotechnic Time Delay Burning Rates: Method and Model Development

AbstractThe burning rates of a slow reacting Mn+Sb2O3 and a fast reacting Si+Pb3O4 time delay composition, filled into lead tubes, were measured with an infrared camera, with two thermocouples and in the form of a fully assembled detonator. The infrared camera method returned values that were on average about 12 % lower than those recorded for the detonators. The temperature profiles measured for the slow burning elements were fully developed, whereas those obtained for the fast burning Si+Pb3O4 elements were not. A numerical model was developed to simulate the Mn+Sb2O3 system. Kinetic parameters were determined by least square fits to the recorded surface temperature profiles. The model made it possible to determine the effect of various property variations on the burning rate. The thermal conductivity of the delay composition was found to have the smallest impact and the heat of reaction the largest effect.

Microstructure control to reduce leakage current of medium and high voltage ceramic varistors based on doped ZnO

The leakage current (If) and the non-linearity coefficient (α) are crucial parameters in varistors. This work, deals with the optimization of the electrical characteristics of medium and high voltage varistors based on the ZnO–Bi2O3–Sb2O3 system. First, the aim was to allow the formation and the stabilization of the spinel phase by reducing the heating rate. To do so, the right sintering temperature and dwell time have to be chosen to obtain a breakdown field suitable for industrial requirements. During cooling, the spinel phase can return to a pyrochlore phase, which contributes to the increase of leakage current. In a second part, this reaction was prevented by faster cooling in an appropriate temperature range. The fine-tuning of both the heating and cooling phases leads to a significant decrease of the leakage current. Moreover, the value of the non-linearity coefficient was increased by 80%, due to better and more homogeneous wetting of the ZnO grains by the Bi-rich phase.

Thermodynamic study of MgO–Sb2O3 system and the stability functions of magnesium antimonite

In this study, the standard Gibbs free energy of formation of MgSb2O4 has been determined by means of the solid-oxide electrolyte EMF technique. A pure-oxygen reference electrode was applied for the first time to this system in an oxygen concentration cell. The EMF values, temperature and the prevailing pressure of the following galvanic cell were measured:(-)Pt,Re,Sb(l),MgO(s),MgSb2O4(s)|YSZ|O2(g),Pt(+).The standard Gibbs free energy of the virtual cell reaction 2Sb(l)+3/2O2(g)+MgO(s)=MgSb2O4(s) was determined to be:ΔrG°/(kJ·mol-1)±2.97=-734.96+0.2645T/K(906≤T/K≤1148).The standard Gibbs free energy of formation of solid MgSb2O4 from its pure component oxides Sb2O3(l)+MgO(s)=MgSb2O4(s) was determined to be:ΔfG°MgSb2O4/(kJ·mol-1)±3.00=-52.75+0.0253T/K(929≤T/K≤1148).The standard Gibbs free energy of formation of solid MgSb2O4 from the elements Mg(l)+2Sb(l)+2O2(g)=MgSb2O4(s) was determined to be:Δf′G°MgSb2O4/(kJ·mol-1)±18.2=-1392+0.4055T/K(973≤T/K≤1148).

Growth and characterizations of lead-free ferroelectric KNN-based crystals

We have grown by flux method centimeter-sized single crystals from pseudo-hexanary Li2O–Na2O–K2O–Nb2O5–Ta2O5–Sb2O3 system. Based on chemical analysis, crystals of compositions (Li0.023Na0.583K0.394)(Nb0.925Ta0.037Sb0.038)O3 and (Li0.034Na0.609K0.357)(Nb0.896Ta0.047Sb0.057)O3 were characterized by X-rays diffraction which revealed a tetragonal structure. The dielectric analysis confirmed that the ferroelectric behavior of these crystals is very sensitive to little changes in composition as previously observed on ceramics. Such high flexibility of the ferroelectric properties in crystals opens the way towards improved understanding of the relations between structure and polarization in solid solutions which may be an alternative to the lead-based materials. Des monocristaux centimétriques issus du système Li2O–Na2O–K2O–Nb2O5–Ta2O5–Sb2O3 ont été obtenus par la méthode des flux. Les cristaux de composition (Li0.023Na0.583K0.394)(Nb0.925Ta0.037Sb0.038)O3 et (Li0.034Na0.609K0.357)(Nb0.896Ta0.047Sb0.057)O3 ont été caractérisés par diffraction des rayons X et se sont avérés appartenir au système quadratique. Leur comportement ferroélectrique spécifique a été confirmé par des mesures diélectriques. Une telle flexibilité des propriétés ferroélectriques de ces cristaux pour de faibles variations de composition ouvre la voie vers une meilleure compréhension des relations entre la structure et la polarisation dans ces solutions solides, qui sont potentiellement une alternative aux matériaux contenant du plomb.

Fire performance of flame retardant polypropylene and polystyrene composites screened with microscale combustion calorimetry

AbstractFlame retardant polypropylene (PP) and polystyrene (PS) materials were prepared by the incorporation of decabromodiphenyl oxide and Sb2O3 in addition to nanoparticles, montmorillonite clay, and carbon nanotubes (CNTs). Their fire performance was screened with microscale combustion calorimetry (MCC) as well as evaluated by cone calorimetry. The decabromodiphenyl oxide–Sb2O3 system exhibited better efficiency in reducing the peak heat release rate (PHRR) of PP compared to PS in the MCC, whereas the trend was the opposite in cone calorimetry. Introduction of clay or CNTs to the decabromodiphenyl oxide–Sb2O3 system was beneficial in reducing the PHRR of both composites in cone calorimetry; however, a reduction in the PHRR in the MCC was only observed in the PS composites. The thermogravimetric analysis (TGA) studies revealed that the fire results from the MCC for the two types of composites were strongly correlated with their thermal degradation traces. There were poor relationships between the parameters of MCC and cone calorimetry, but good correlation between the temperature difference of the first and second peak of mass loss rate in the TGA, temperature at the PHRR in the MCC, and fire performance index in the cone calorimetry. Copyright © 2010 John Wiley & Sons, Ltd.

Effect of powder bed on the microstructure and electrical properties of Bi2O3- and Sb2O3-doped ZnO

The effects of powder bed on the microstructure and electrical properties of Bi2O3- and Sb2O3-doped ZnO specimens are investigated in the present study. By using a sufficient amount of powder bed, the weight loss of Bi2O3 reduces from >95 to <20%. The reduction of weight loss enhances significantly the densification and grain growth of ZnO. Furthermore, the use of powder bed can also reduce the size distribution of ZnO grains. Nevertheless, the presence of Bi2O3 residue results in the formation of a pyrochlore phase (Zn2Bi3Sb3O14) during the cooling down stage; its presence is detrimental to the nonlinear characteristics of ZnO–Bi2O3–Sb2O3 system.

Antimony Dispersion and Phase Evolution in the Sb2O3−Fe2O3 System

This paper studies the antimony spreading and segregation that occurred along with the oxidation and solid-state reactions in the Fe2O3-Sb2O3 system. XRD, SEM, TG-DSC and particularly XPS were employed for characterizations. Sb2O4 and FeSbO4 are the only new phases detected. The formation of FeSbO4 is a more exothermic but slower reaction than oxidation of Sb2O3. A mechanical grinding of Sb2O3 and Fe2O3 leads to a significant dispersion of Sb2O3 possibly because of its low hardness. Dispersion of reference Sb2O4 in this way is negligible. During the heating of a mixture of Sb2O3 and Fe2O3 with an atomic ratio of Sb/Fe = 0.5 at 200-1000 degrees C in ambient air, the thermal spreading of Sb2O3 onto Fe2O3 increases with increasing temperature until Sb2O3 is oxidized into Sb2O4. The surface atomic ratio of Sb/Fe measured by XPS, R(Sb/Fe), reaches a maximum around 400 degrees C. The complete oxidation of Sb2O3 leads to a decrease in R(Sb/Fe) because of poorer dispersibility of Sb2O4. The formation of FeSbO4 starting at ca. 800 degrees C causes a further decrease in R(Sb/Fe), but the R(Sb/Fe) is still 3.2 times the nominal bulk Sb/Fe ratio when the Sb2O4 is completely transformed into FeSbO4.

Note on ferriglass formation in the Fe2O3–BaO–B2O3–Sb2O3 system

Note on ferriglass formation in the Fe2O3–BaO–B2O3–Sb2O3 system

Structural approach of the ( xPbCl 2 − (1 − x)Sb 2O 3) glass system

A structural approach of xPbCl2, (1 − x)Sb2O3 glasses, quenched from the melt, is proposed. The crystallization process of the glasses is analyzed and a Raman scattering investigation is reported. The two investigations give valuable information on the structural arrangement of the glass network. Observations within the xPbCl2, (1 − x)Sb2O3 system show variations of local structure and a comparison is made with previously reported data for some Sb or As based glasses.

Electrical properties of oxide glass thin films of the TeO2Sb2O3 system

Electrical properties of oxide glass thin films of the TeO2Sb2O3 system