85 research outputs found
Structural, Optical, Magnetic and Photon Attenuation of Novel Potassium Lead Borate Glasses Doped with MnO
Potassium lead borate glasses doped with MnO (40B2O3 + 40PbO + (20-x)K2O + xMnO: x = 0–5 mol%) have been prepared via standard melting quenching process. The impact of MnO on the structure, optical, magnetic and gamma-ray protection properties of pottisium lead borate glasses have been examined. The density was increased from 4.83to 5.23 g/cm3 as MnO content increased while the molar volume of prepared glass sample was decreased from 28.112 to 25.755 cm3/mol. The obtained direct optical gap (Eg) values were 2.84, 2.59, 2.41, 2.19, 1.95, and 1.84 eV for the Mn-x (x = 0, 1, 2, 3, 4, and 5) glass samples, respectively. Fourier-transform infrared spectroscopy (FTIR) spectra demonstrated that as the MnO concentration increases in the glass network the intensity and width of the IR bands were increased. The magnetic measurement revealed that the magnetic saturation (Ms) was decreased while the magnetic coercivity (Hc) was increased with increasing MnO substitution ratio. The linear attenuation coefficient of the μMn-glass follows the order: µMn-0 < µMn-1 < µMn-2 < µMn-3 < µMn-4 < µMn-5. Half value layer (HVL) rises as µ decreases and vice versa. The range of the HVL is 0.002–3.378, 0.002–3.334, 0.002–3.291, 0.002–3.248, 0.002–3.176, and 0.002–3.106 cm for Mn-x (x = 0, 1, 2, 3, 4, and5). The trend of effective atomic number (Zeff) variation is related to that of both linear and mass attenuation coefficients (µ and µm). The produced Mn-glasses can be employed in a variety of optical, magnetic and radiation protective applications. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature
A comprehensive study on optical features, gamma photon buildup factors and neutron shielding capability of B2O3-SB2O3-LI2O-BI2O3 glasses
ABSTRACT. Linear, nonlinear optical properties, photon buildup factors, and neutron shielding capability of glasses with chemical composition (65-x)B2O3-10Sb2O3-25Li2O-xBi2O3, where x = 0 (BSLB0) – 20 (BSLB20) mol% with steps of 4 mol% were examined. Molar refractivity (Rmolar) and molar polarizability (αmolar) were increased as Bi2O3 content mol% increase in the examined BSLB-glasses. The values of metallization criterion (Mcriterion) confirmed that the BSLB-glasses were non-metallic materials. The static (εstatic) and optical (εoptical) dielectric constants having the same trend of the refractive index (noptical). Values of optical electronegativity (χ*) were reduced from 0.825 for BSLB0 (Bi2O3 = 0 mol%) glasses to 0.758 for BSLB20 (Bi2O3 = 20 mol%) glasses. The linear electric/dielectric susceptibility (χ(1)) increased from 0.370 to 0.397. The nonlinear optical susceptibility (χ3) and nonlinear refractive index n2optical were enhanced by increasing Bi2O3 content in the BSLB-glasses. The BSLB20 glasses presented the least exposure and energy absorption build-up factors (EBF and EABF) at all considered thickness. BSLB20 sample achieved the best fast neutron removal cross section ( ) shield among all glasses. The total stopping powers (TSP) follows the trend (TSP)BSLB0 < (TSP)BSLB4 < (TSP)BSLB8 < (TSP)BSLB12 < (TSP)BSLB16 < (TSP)BSLB20. The electron absorbing and hence shielding capacity of the BSLB-glasses improves as their Bi2O3 content increase.
KEY WORDS: Antimony lithium-borate glasses, Optical properties, Buildup factors, Neutron shielding
Bull. Chem. Soc. Ethiop. 2022, 36(4), 949-962.
DOI: https://dx.doi.org/10.4314/bcse.v36i4.19  
Characterization of zinc lead-borate glasses doped with Fe3+ ions: optical, dielectric, and ac-conductivity investigations
The optical, dielectric response, and ac-conductivity properties for six glasses of zinc lead-borate doped with different contents of Fe3+ (Fe2O3 = 0 to 10 wt%) have been investigated. UV–Vis spectra in 190–1100 nm wavelength have been carried out. Band gaps for optical energy (EOptical), Urbach’s energy (EU), index of refraction (n), steepness parameter (S), energy dispersion parameter of refractive index (Ed), single-oscillator energy (Eo), the dispersion refractive index (no), minimum reflectance wavelength (λo), and oscillator strength (So) were evaluated. Results reveal that the indirect energy gap varies from 2.57 to 1.01 eV, while the direct energy gap takes values from 2.80 to 1.45 eV. The EU values change from 0.232 to 0.966 eV for glasses with Fe2O3 = 0 and 10 wt%, respectively. Also, S and λo decrease with the enhancement of Fe2O3 content. The dielectric response and ac-conductivity of the prepared glasses were investigated by broadband dielectric spectroscopy, BDS, in the frequency range from 0.1 Hz to 10 MHz and at temperatures ranging between 300 and 430 K. Two trends of activation plot have been observed in the conductivity of the samples with low content of Fe2O3. Although these samples show a perfect insulation features, they obey an anomalous behavior at higher temperatures. Therefore, the investigated glasses can be applied in several optical and optoelectronic devices. © 2020, Springer Science+Business Media, LLC, part of Springer Nature
Effects of ternary mixture of chalcogens on the Fel .02Se superconducting propertie
The present work was supported by the Ministry of Education and Science of Russia and by the Ural Branch of RAS (Project No 15-17-2-22)
Influence of Increasing SnO2 Content on the Mechanical, Optical, and Gamma-Ray Shielding Characteristics of a Lithium Zinc Borate Glass System
A series of six samples were prepared based on the chemical composition of 65B2O3 + 20ZnO + (15-x)LiF + xSnO2 (where x = 0, 0.25, 0.5, 0.75, 1, and 1.25 mol%) to study the role of SnO2 on enhancing the optical and radiation attenuation capacity of the prepared glasses. The preparation of the glass series was performed using the melt quenching method at 1100 °C for 60 min. The density of the fabricated samples was measured using an MH-300A densimeter. The optical parameters of the fabricated glasses were calculated based on the spectrum recorded by a Cary 5000 UV–Vis–NIR double beam spectrophotometer in a wavelength range of 200 to 3000 nm. Furthermore, Monte Carlo simulation code and the XCOM online database were used to estimate the gamma-ray shielding capacity of the fabricated samples from 0.244 to 2.506 MeV. The results show enhanced gamma-ray shielding capacity due to the replacement of LiF by SnO2. The linear attenuation coefficient at 0.244 MeV was enhanced from 0.352 to 0.389 cm−1. The half-value thickness of the investigated glasses decreased from 1.967 to 1.784 cm when the increasing addition of SnO2 from 0 to 1.25 mol%. © 2022, The Author(s).The authors express their gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project (PNURSP2022R2), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
Effect of the tellurium for selenium substitution on the phase composition and electrical resistivity of Fe7(Se1-xTex)8
The discovery of Fe(Se, Te)-type superconductors has attracted much attention due to their simplest crystal structure among the new families of iron-based layered compounds. However, the Fe(Se, Te) samples often exhibit an impurity hexagonal phase of the NiAs-type together with the main superconducting phase having a tetragonal PbO-type phase [1]. The aim of the present work is to study how the coexistence of the tetragonal and hexagonal phases in the Fe7(Se,Te)8 samples influences their superconducting properties bearing in mind the limited solubility of tellurium in Fe7(Se,Te)8.The present work was supported by RFBR (projects No 16-02-00480 and 16-03-00733)
Examinations the Optical, Mechanical, and Shielding Properties of Ag2O doped B2O3–Bi2O3–SrF2–Na2O Glasses for Gamma Ray Shield Applications
A series of five glass samples have a chemical composition of (55-x) B2O3 + 5 Bi2O3 + 20SrF2 + 20Na2O + xAg2O with varied doping ratios x = 0, 1, 2, 3, and 4 mol% were fabricated using the melt quenching technique to study the effect of B2O3 replacement by Ag2O on the physical, mechanical, optical and gamma-ray shielding capacity of the fabricated glasses. The Cary 5000 UV–Vis–NIR measured the optical absorption in the wavelength range between 200 and 3000 nm. Based on the measured optical absorption, energy (direct/indirect) bandgap and Urbach energy were calculated. Moreover, the measured samples density, molar volume, packing density, dissociation energy, and mechanical properties for the fabricated glasses were calculated using the concepts of the Makishima-Mackenzie model. In this regard, the microhardness was decreased from 4.070 to 3.931 GPa with raising the Ag2O concentration. The effect of B2O3 replacement on the shielding capacity was also evaluated using the Monte Carlo simulation. The simulation results showed that the replacement of B2O3 causes a significant increase in the shielding parameters like linear attenuation coefficient and radiation shielding capacity. The best radiation shielding properties were achieved for a glass sample with 4 mol% Ag2O compound. Its linear attenuation coefficient varied between 8.091 and 0.134 cm−1, raising the gamma photon energy between 0.059 and 2.506 MeV. © 2022, The Author(s)
Impact of 3dmetal oxides on the structure and properties of Fe(Se,Te)-type superconductors
The present work was supported by RFBR (projects No 16-02-00480 and 16-03-00733) the Ministry of Education and Science of Russia (project No 1362)
Lead borate glasses and synergistic impact of lanthanum oxide additive: optical and nuclear radiation shielding behaviors
Composition of (50 − x) B2O3–30PbO–20ZnO–xLa2O3 (x = 0, 1.5, 3, 4.5, and 6) wt% glass system were synthesized using quench melt technique and simulated for their nuclear radiation shielding properties. Moreover, UV–visible absorption spectrum among 190–1100 nm and the glass optical parameters were measured. The optical energy gap (Eg), the single-oscillator energy (Eo), the dispersion energy parameter (Ed), refractive index (n), and refractive dispersion index (no) were estimated. The obtained results indicated that (Eg) was decreased with increasing La2O3 content, but the refractive index (n) was increased. The addition of La2O3 to glass network could provide preferable shielding features. The chosen amount of La and another metal oxide has been added to the glass. Shielding parameters such as half-value layer (HVL), mean free path (MFP), mass attenuation coefficient (MAC), and exposure rate in the photon energy range 15–300 keV have been simulated by MicroShield software. These results illustrate that the La5 glass sample has the best radiation shielding properties, among other investigated glasses. This type of glass sample can utilize for the construction of the monitoring screening windows in radiation areas, plats, or screening windows in X-ray diagnostic and for the walls of CT-scanner rooms. © 2020, Springer Science+Business Media, LLC, part of Springer Nature
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