Oxygen Molar Volume Research Articles

Synthesis, crystallization and properties of TeO2/TiO2/B2O3 glasses

This study continues our previous investigations on non-traditional tellurite glasses. Ternary TeO2/TiO2/B2O3 glasses have been obtained applying melt quenching method (up-down) from compositions containing high TeO2 content (60 and 80 mol%). It was established that transparent and brownish coloured homogeneous glasses were obtained. Some physical parameters (density, molar volume, oxygen molar volume and oxygen packing density) were estimated and they gave additional, useful information for the network connectivity. The analysis of IR spectra showed that the glass network consists of TeO4 (tbp), TeO3 (tp), BO3 and BO4 units. The UV–Vis spectroscopy established that glasses containing the highest TeO2 content (80 mol%) and lowest B2O3 amount (10 mol%) exhibited the lowest cut-off value (368 nm) and highest Eg − 3.37 eV.

Investigations on Structural and Optical Properties of Various Modifier Oxides (MO = ZnO, CdO, BaO, and PbO) Containing Bismuth Borate Lithium Glasses

Bismuth based quaternary glasses with compositions BiBLM: 50Bi2O3–20B2O3–15Li2O–15MO (where MO = ZnO, CdO, BaO, and PbO) were processed by conventional melt quenching. The effectiveness of various modifier oxides on the optical and structural properties of the developed glasses was studied systematically by XRD, DSC, FTIR, Raman, and optical absorption (OA) measurements. The synthesized glass specimens were characterized by XRD and the patterns demonstrated an amorphous nature. The physical characteristics such as molar mass, density, and OPD values were found to increase with an increase in the molar mass of the modifier oxides, while there was a decrement in oxygen molar volume, thus resulting in decrement of complete molar volume of the prepared glasses. From DSC analysis, incorrigible reduction and enhancement of Tg and thermal stability among various modifier oxides in the glass network was noticed. Optical absorption data for glass specimens have confirmed the decrease in both direct and indirect optical band gap values among various modifier oxides incorporation. These investigations support the obtained Urbach energy (UE) and metallization criteria of synthesized glasses. The ionic characteristic for the glass specimens were confirmed by the values of electronic polarizability and electronegativity. The Raman and FT-IR spectra of the glass specimens displayed the existence of BiO3, BiO6, ZnO4, CdO4, BaO4, BO3, PbO4, and BO4 structural units within the glass matrix. These structural results can support the applications of as-developed glasses in the area of photonics.

Physical, structural and nuclear radiation shielding behaviour of xBaO-(0.30-x)MgO-0.10Na2O-0.10Al2O3-0.50B2O3 glass matrix

In the present investigations, six cylindrical shaped glass sample having chemical composition x BaO-(0.30-x) MgO-0.10Na2O-0.10Al2O3-0.50B2O3 (x = 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30 mol fraction) were prepared by melt quenching technique. The density, molar volume, oxygen packing density (OPD), oxygen molar volume (OMV), Poisson's ratio, barium inter ionic distance, Polaron radius and field strength were calculated for the prepared glass samples. The values of linear attenuation coefficients (LAC) were measured experimentally by using narrow beam transmission geometry in the gamma photon energy range of 59.54–1332 keV. In order to ascertain the application of the prepared glasses in the field of radiation protection and design, the values of LAC were used to calculate various gamma ray interaction parameters namely half value layer (HVL), Radiation Protection Efficiency (RPE), Mass Attenuation Coefficient (MAC), effective atomic number (Zeff), electron density (Ne) and Exposure Buildup Factors (EBFs). The values of fast neutron removal cross sections (∑R cm−1) were also calculated for the prepared glass matrix. The theoretical values of attenuation parameters were determined using online software Phy-X/PSD and FLUKA (Monte-Carlo) simulation code. Excellent agreements have been observed between experimental, theoretical and simulation results for the prepared glass samples. Furthermore, the radiation shielding properties for the prepared glass samples were compared with conventional used concretes and commercial radiation shielding glass (RS253 G-18). On the basis of the obtained results, it has been reported that the prepared glass samples possess satisfactory physical reliability and superior shielding efficiency against gamma rays and fast neutrons as compared to conventional/commercial shielding materials.

Investigations on physical, structural and nuclear radiation shielding behaviour of niobium–bismuth–cadmium–zinc borate glass system

In the present paper, glass sample with the chemical composition xNb2O5+0.20Bi2O3+0.20CdO+0.10ZnO+ (0.50-x)B2O3 (where x = 0.05, 0.10, 0.15, 0.20, 0.25 mol fraction) were prepared by melt quenching-annealing technique. The density, molar volume, oxygen molar volume (OMV) of the glass samples are found to increase increases from 5.35 to 5.65 gcm−3, 32.69–37.32 cm3/mole, 14.323–14336 cm3/mole, respectively, with the increase in molar concentration of Niobium pentoxide. The value of Poisson's ratio shows a very small variation in the range of 0.240–0.247 for the present glass matrix, however these results confirms that the prepared glass samples have high cross link density. The linear attenuation coefficients were measured experimentally by employing narrow beam transmission geometry (total scatter acceptance angle = 2.22°) with NaI(Tl) spectroscopy in the gamma photon energy range of 59.54–1332 keV. These values of linear attenuation coefficient were then further used to calculate other attenuation parameters namely Half Value Layer (HVL), Radiation Protection Efficiency (RPE), Mass Attenuation Coefficient (MAC), effective atomic number (Zeff), electron density (Ne) and Buildup Factor (BF). Measured values of attenuation parameters have also been compared the values obtained theoretically using online software Phy-X/PSD and Py-MLBUF as well as with values obtained through FLUKA (Monte-Carlo) simulations code. Excellent agreements have been observed between experimental, theoretical and simulation results for the prepared glass samples. In addition to this, fast neutron removal cross sections (∑R cm−1) were calculated for the glass matrix under investigations. On the basis of the obtained results, it has been reported that the prepared glass samples possess superior shielding efficiency against gamma rays and fast neutrons as compared to conventional shielding materials.

Nuclear radiation shielding characteristics and physical, optical, mechanical, and thermal properties of lithium-borotellurite glass doped with Rb2O

The current paper addresses the influence of Rb2O in the lithium-borotellurite (LBT) glass system for the first time. For this, the glass system (25-x)Li2O–15B2O3–60TeO2-xRb2O was designed where x: 0, 5, 10, 15, 20, and 25 mol%. An extensive investigation was carried out to understand the alterations in physical, optical, thermal, and mechanical properties with the use of theoretical calculations. The user-friendly Phy-X/PSD software was employed to demonstrate the nuclear radiation protection properties. From physical property calculations, the addition of Rb2O from 0 to 25 mol% increased average molecular weight (AMW) from 113.68 to 152.94 g mol−1 and glass density (ρglass) from 4.2743 to 4.7710 g cm−3. Likewise, molar volume (Vm), oxygen molar volume (VO), oxygen packing density (OPD), and number of bonds per unit volume (nb) were considerably changed by the increasing Rb2O concentration. According to the optical calculations, the refractive index (n) increased from 2.3348 to 2.6104, while the dielectric constant (ε) increased from 5.45 to 6.81. Moreover, the metallization criterion (M) showed a decreasing trend, and implied increasing insulation with the increase in Rb2O in the glass system. For thermal property estimations, viscosity versus temperature profiles clearly indicated that all R-series have the ability to form glass, but decreasing the Li2O caused an increment in glass melting temperature. The mechanical moduli determinations via the Mackenzi-Makishima model demonstrated that Young's (E), bulk (B), shear (S), and longitudinal (L) moduli were gradually decreased by introducing Rb2O into the glass network. From the perspective of radiation shielding calculations, the essential parameter, linear attenuation coefficient (LAC), effectively improved by increasing the doping rate of Rb2O. Based upon the LAC values, the other critical parameters such as mean free path (MFP), half-value layer (HVL), and effective atomic number (Zeff) were successfully evaluated. Additionally, build-up factors such as exposure (EBF) and energy absorption (EABF) were assessed with the implementation of G-P progression. They showed that sample-R25 ensured better gamma-ray shielding properties compared to the other samples. Lastly, fast neutron removal cross-section (FNRCS) determinations displayed decreasing behaviour with the increasing Rb2O content, which is not convenient for effective neutron shielding abilities. All in all, the Rb2O-reinforced borotellurite glass can serve as an alternative radiation shielding material.

LiKBPbX glasses: Physical, structural and gamma ray shielding competence

The LiKBPbX glasses have been fabricated with the standard melt quenching methodology. The density and molar volume of glass systems change from 2.2057 g/cm3 to 2.9427 g/cm3 and 70.569–101.283 cm3 respectively with the increase in dopant concentration of PbO mol%. The Oxygen packing density (OPD) of prepared glasses is decreased from 75.01 to 58.108, whereas the optical basicity is increased from 0.668 to 0.772. The oxygen molar volume (OMV) of prepared samples varies from 13.33 cm3 to 17.21 cm3. The XRD spectrum represents two broad humps around 20–300 and 40–500 and absence of any sharp peak confirm that the structures of glasses are amorphous in nature. There are five bands observed in FTIR spectra from 400 to 600, 600–800, 800–1200, 1200–1500 and 1500–1800 cm−1 respectively. These bands are assigned due to the various bending and symmetric as well as asymmetric stretching vibrations of the groups present in the glassy network. The gamma ray shielding behavior has been studied for the energies from 0.015 MeV to 15 MeV. LiKBPb20 glass is the most space-efficient gamma shield.

SrO-SiO2-B2O3-ZrO2 glass system: Effects of varying SrO and BaO compositions to physical and optical properties, and radiation shielding using EPDL2017 photoatomic library

The physical, optical, and radiation shielding properties of the SrO-SiO2-B2O3-ZrO2 glass system with varying SrO and BaO compositions were investigated. The optical basicity, oxygen packing density (OPD), and oxygen molar volume (OMV) of the glasses ranges from 0.742 to 0.786, 70.408 to 66.16, and 12.202–15.114 cm3/mol respectively as the mol% concentration of BaO from 0 mol% to 40 mol%. The refractive index (n), dielectric constant (ε) and optical dielectric constant (pdpdt) decrease sharply as BaO content increases from 0% to 10%, thereafter a slight increment in n, ε, and pdpdt is observed with an increase in BaO content from 10% to 30% and with further increase in BaO content beyond 30% again decrease in the values of n, ε, and pdpdt is observed. The molar refractivity (Rm) and molar Polarizibility (αm) are affected by BaO content. In the broader perspective, Rm and αm decrease sharply as BaO content increases from 0% to 10%, thereafter a slight increment is observed with an increase in BaO content from 10% to 40%. The metallization criterion (M) and the value of reflection loss (RL) confirm that the present glasses show non-metallic character or insulating in nature. While replacing the composition SrO with BaO improves the glasses' capabilities to shield gamma radiation at low gamma energies (284–826 keV), their shielding capabilities slightly deteriorates at high gamma energies (1173–1333 keV).

Mechanical and Gamma-Ray Interaction Studies of PbO–MoO3–Li2O–B2O3 Glass System for Shielding Applications in The Low Energy Region: A Theoretical Approach

The mechanical and radiation shielding properties for the PbO–MoO3–Li2O–B2O3 glass system were theoretically investigated in this paper. The PbO–MoO3–Li2O–B2O3 glass system (coded as investigated glasses) was fabricated using the melt quenching mechanism. The optical packing density (OPD) increases from 75.563 to 84.366, and oxygen molar volume (OMV) decreases from 13.234 to 11.853 cm3/mol when increasing the PbO concentration. The values of elastic moduli decreased from 47.06 to 39.67 GPa for Young, from 33.51 to 32.41 GPa for bulk, from 19.82 to 16.29 GPa for shear and from 59.94 to 54.14 GPa for longitudinal moduli as the PbO is increased. The radiation attenuation characteristics were reported at the photon energies used in diagnostic radiology. The mass attenuation coefficient (MAC) was evaluated using the three photoatomic data libraries EPICS2017, EPDL97, and XCOM, available in the EpiXS and Phy-X programs. The MAC for the five investigated glasses at 20 keV was much higher than the MAC at 40, 60 and 80 keV. The MAC for investigated glasses increased with the addition of PbO, with Pb-S1 demonstrating the lowest MAC, and Pb-S5 demonstrating the highest MAC. Additionally, the rate of the increment of MAC at 20 keV as the concentration of PbO increased was higher than that at 40, 60 and 80 keV. The effective atomic number (EAN) was determined using Phy-X program. The EAN follows the trend: Pb-S5 > Pb-S4 > Pb-S3 > Pb-S2 > Pb-S1. The EAN results proved that the glass with low amounts of B2O3 and higher amounts of PbO had good attenuation features. The EAN had the maximum values of 73.55–76.67 at 20 keV, whereas the lowest values occurred at 80 keV and varied between 53.63 and 63.39. The half-value layer (HVL) results showed that the Pb-S1 glass had the greatest HVL, while Pb-S5 had the least. There is a higher discrepancy between the tenth-value layer values at 80 keV than at 20 keV. At 20 keV, the difference between the highest and lowest TVL values (Pb-S1 and Pb-S5) was only 0.004 cm, while the difference at 80 keV was 0.152 cm. Pb-S5 is the most space-efficient radiation shield.

Probing of nuclear radiation attenuation and mechanical features for lithium bismuth borate glasses with improving Bi2O3 content for B2O3 + Li2O amounts

Against photon energies extending from 0.015 to 15 MeV, MCNPX, FLUKA and PHITS codes are operated to simulate mass attenuation coefficients (μ/ρ) for a total of ten B2O3-Bi2O3-Li2O glass compositions with added Bi2O3 amount from 10 to 55 mol% (5 mol% growth gradually) as a substitute for total (B2O3 + Li2O) mol% content. All the computed μ/ρ values correctness is examined by Py-MLBUF and WinXCOM programs’ μ/ρ outcomes and we found a good agreement among them. 55Bi2O3-35B2O3-10Li2O (mol%) glass half-value layer (HVL) and mean free path (MFP) quantities are compared with distinct commercial γ-ray attenuating glasses, alloys, polymers, concretes and lead and ceramics corresponding values. Next, equivalent atomic numbers (Zeq) and by employing geometric progression (G–P) fitting method at 1–40 mfp PDs (penetration depths), at 0.015–15 MeV energy range ‘buildup factors’ were calculated. At all chosen twenty-five energies derived radiation protection efficiency (RPE) results assured investigated samples exemplary competence for low energy photons absorption. Applying SRIM codes ΨP and ΦP and ΨA and ΦA (mass stopping powers (MSPs) and projected ranges (PRs) for protons and α-particles), and making use of ESTAR database ΨE (electron MSP) and continuous slowing‐down approximation (CSDA) range for electrons are determined at KE (kinetic energy) range of 0.015–15 MeV. Moreover, fast neutron removal cross-sections (ΣR), for 0.0253 eV energy neutrons absorption cross-sections have been estimated. Deduced ΣR was altered at 0.1105–0.1205 cm−1 range with Bi2O3 inclusion in studied samples. 10Bi2O3-70B2O3-20Li2O (mol%) glass has greater total cross-section (=23.251 cm−1) for thermal neutrons absorption while 55Bi2O3-35B2O3-10Li2O (mol%) sample exhibits quality shielding factors for photons and fast neutrons confirming the included Bi2O3 positive impact. Along with nuclear attenuation features various physical and mechanical aspects are also inspected. Derived Vm (molar volume), OPD (oxygen packing density), Vo (oxygen molar volume), Vt (packing density) and Gt (dissociation energy per unit volume) values indicated glasses rigidity. Following Makishima–Mackenzie's theoretical model primary mechanical features like Y, K, S and L (Young's, bulk, shear and longitudinal modulus) and σ (Poisson's ratio) are evaluated where 10Bi2O3-70B2O3-20Li2O (mol%) glass shows better elastic moduli in all samples.

Fabrication and characterization of barium based bioactive glasses in terms of physical, structural, mechanical and radiation shielding properties

A novel bioactive glass system 20SiO2- 7.5Na2O- 7.5K2O- (65-x)P2O5- xBaO (where x = 2.5, 5.0, 7.5 and 10.0 mol %) has been fabricated using melt quenching method and corresponding samples named as GB1, GB2, GB3 and GB4, respectively. The formation of glass has been confirmed by X-ray diffraction (XRD) analysis. Physical and structural properties include measurement of density (ρGlass), molar volume (Vm), oxygen packing density (OPD), oxygen molar volume (Vmo), ionic concentration measurement (N), interionic distance (R), Polaron radius (Rp) and Phosphorous molar volume Vmpfor all the selected glass samples. Mechanical properties include packing density (Vt), Young's modulus (Y), bulk modulus (K), shear modulus (S), longitudinal modulus (L), hardness (H) and Poisson's ratio (σ) has been studied using Makishima-Mackenzie and Rocherulle models. Radiation shielding properties viz. mass attenuation coefficient (MAC), effective atomic number (EAN), effective electron number (EEN), half value layer (HVL) and tenth value layer (TVL) have been evaluated theoretically using the WinXCom and PSD software packages for all the glass samples and experimentally verified at selected photon energies of 511 keV (Na22), 662 keV (Cs137), 1173 keV and 1332 keV (Co60) using gamma ray spectroscopy. Additionally, some of these radiation shielding properties for the fabricated glasses were compared with commercially used concretes, radiation shielding glass (RS253 G-18) and registered 45S5 Bioglass®. GB4 glass sample is found to possess all the qualities which are essential for an ideal radiation shielding material and can easily replace commercially used radiation shielding materials.

Synthesis, physical and mechanical properties of lead strontium titanate glass ceramics

Various glass composition, x = 0.0, 0.2, 0.4 and 0.6 were synthesized in a bulky glass system 64 [(Pb1-xSrx)OTiO2]-25 [(2SiO2·B2O3)]-[3BaO·7K2O]-1La2O3 using melt-quenching technique. All synthesized glasses were converted into their glass ceramics via a scalable solid-state reaction method. Several physical parameters were investigated such as green/sintered density, oxygen packing density, ionic concentrations, molar volume, and molar mass respectively. For phase identification of the sintered glass ceramics, X-Ray diffraction measurements were performed. Further, to evaluate structural properties of the sintered glass ceramic samples, FTIR spectroscopy was also performed. To reveal the grain/grain boundaries and elemental analysis, surface morphology of the sintered glass ceramics followed by energy dispersive X-ray analysis was evaluated by employing a scanning electron microscopic technique. Further, to study the mechanical properties of these glass ceramics, tribological tests were also conducted, and revealed the maximum value of compressive strength, 322 MPa for glass ceramic, x = 0.6 sintered at 796 °C.

Exploration on dysprosium ions doped zinc barium boro-tellurite glasses towards radiation screening and photonic applications

Dy3+ ions doped zinc barium Boro-tellurite glasses are prepared in the laboratory employing the melt quenching technique. The physical properties like density and refractive index are determined for each glass and found a progressive increase as moved from 0% to 40% of Zn content. This can be explained based on the formation of bridging oxygen (BO) and the proportional decline of the molar volume of the glasses. Structural parameters are evaluated to assess the nature of network bonding within the glasses. Molar volume of oxygen and Oxygen packing density values are contrasting. From this result, one can understand the creation of bridging or Non-bridging oxygen (BO/NBO) in the network. The obtained bond density values additionally support this information on oxygen lattice creation. The optical properties like optical bandgap, Urbach energy, and band tailing parameter are also obtained from the absorption spectra. Additionally, radiation shielding properties for the prepared glasses are investigated using Phy-X/PSD software. The radiation shielding parameters were demonstrated to have strong energy dependence at low energies. The effect of changing the proportion of barium and zinc content on the structural and radiation shielding properties is determined and well interpreted. Since the present glass is designed to be Pb-free, these glasses are non-toxic and eco-friendly. The results reveal the fact that the current glasses are more suitable for radiation protection applications. Also, the barium and zinc cations ratio's influence on the luminescence ability of the prepared glasses was explored through emission and luminescence decay measurements.

Down-conversion luminescence and shielding parameters of Dy3+: NFBT glass for white LED and radiation applications

A new kind of dysprosium (Dy3+) ions doped niobium fluoro borotellurite (NFBT) glass with compositions (35- x )TeO2 + 30H3 BO3 + 15Nb2O5 + 10SrCO3 + 10CdF2 + x Dy 2O3 (where x = 0.05, 0.3, 0.5, 1, 2 and 3 in wt. %, hereafter refers as to Dy 3+ ions’ concentration) was fabricated with melt quenching method and characterized through X-ray diffraction, physical (density (ρ), molar volume of oxygen (V o), and optical basicity ( th), etc.), visible absorption, excitation, emission and lifetime measurements. Its density increases while its molar volume decreases with increase of Dy3+ ions, which indicates that the glass becomes more compact. The absorption spectrum shows the various characteristic peaks of Dy3+ ions attributed to the transitions from the 6H 15/2 ground level to the different excited energy levels. The oscillator strengths and Judd-Ofelt intensity parameters (W l =2, 4 & 6) were articulated from the optical absorption spectrum. The photoluminescence spectrum reveals that this NFBT glass has several emission bands, corresponding to 4F 9/2 → 6H 15/2 (blue), 4F 9/2 → 6H 13/2 (yellow) and 4F 9/2 → 6H 11/2 (red) transitions, respectively. The emission intensity increased with Dy3+ ions concentration from 0.05 wt. % to 1 wt. %, after that the concentration quenching was observed for higher concentrations (2 & 3 wt. %). The non-exponential decay curves were analysed with Inokuti-Hirayama (IH) model ( S =6), indicating a nature of dipoledipole interaction between the donor and the acceptor of Dy3+ ions. The Commission International de’Eclairage (CIE 1931 (x , y) and CIE 1976 ( u , v )) coordinates and the correlated color temperature (CCT) values clearly show that the present glass can be useful in cool white light (CCT>4000 K) region. Moreover, mass attenuation coefficient (μ / ρ), and effective atomic number (Z eff) parameters were also articulated through Phy-X/PSD program. Hence, the results indicate that the prepared glasses could be suitable for laser, smart white LED (1DyNFBT) and gamma ray shielding (3DyNFBT) applications. • A novel series of Dy 3+ : NFBT glasses were prepared with melt quenching. • Luminescence and colorimetric parameters (CIE, CP , CCT, Y/B ratio) were evaluated. • Gamma radiation shielding parameters (MAC, HVL, MFP, Ʃ R , Z eff , etc.) were analysed. • 1DyNFBT and 3DyNFBT glasses can be suggested for WLED and gamma ray shielding applications.

Effect of Sb2O4 on structural, physical and optical properties of sodium zinc borate glasses

Abstract Antimony doped sodium zinc borate glasses of composition [(65-x) B2O3-10ZnO-25Na2O-xSb2O4] (where x = 0, 5, 10, 15 and 20 in mol%) were prepared by using the conventional melt quenching technique. The characterization of the samples was done by X-ray diffraction. XRD pattern revealed the amorphous nature of the prepared samples. Various physical and optical parameters such as density, molar volume, oxygen molar volume, oxygen packing density, optical bandgap energy and Urbach energy were evaluated. The opposite trend between density and molar volume as well as the opposite behaviour between oxygen molar volume and oxygen backing density revealed that the glass samples become less open. FTIR spectra have been investigated at room temperature and used to estimate N4 ratio and its dependent on composition. FTIR analysis showed that antimony oxide acts as a modifier in the borate glass doped with ZnO and Na2O. The observed data clearly suggests that the investigated glass samples may be used for optical limiting applications.

Gamma radiation shielding and structural features for barium strontium boro-tellurite glass modified with various concentrations of molybdenum oxide

In the present study, series of 20BaO-10SrO-30TeO2-(40-x)B2O3-xMoO3 where (x= 0, 5, 10, & 15 mol%) was synthesized via standard melt quench technique. The XRD results affirm the amorphous nature for all glasses, while the FTIR confirms the functional group's existence for TeO2 and B2O3. Various parameters were calculated to define the physical features of the glass samples, like molar volume, density, packing density, Poisson's ratio, oxygen packing density, and oxygen molar volume. The shielding features like mass attenuation coefficient, mean free path, equivalent atomic number, half-value layer, and tenth value layer, specific gamma-ray, gamma dose rate, the specific absorbed fraction of the energy, gamma transmission factor, removal cross-section for fas neutron (∑R) were computed and determined theoretically by using Phy-X. The addition of MoO3 instead of B2O3 in glass samples improves all the structural and shielding features, indicating that glass materials can be used as a good radiation shielding absorber.

The effect of Nb2O5 on waste soda‐lime glass in gamma‐rays shielding applications

Transparent waste soda-lime glass (SLS) reinforced with Nb2O5 (0.005, 0.05, and 0.5 wt%) was successfully synthesized using a conventional melting technique for gamma-radiation attenuation applications. The synthesized glass series (RG, RGN1 to RGN3) were then subjected to some physical, optical, and radiation shielding measurements. The physical measurements and computations showed that the increasing content of Nb2O5 increased glass density (ρglass), molar volume (Vm), and oxygen molar volume (OMV), however, decreased oxygen-packing density (OPD). Moreover, several optical parameters, such as the refractive index (n), dielectric constant (ϵ), and metallization criterion (M), were evaluated. One can say that the optical and physical properties can be improved owing to the addition of Nb2O5 in waste SLS glass. The gamma-ray transmission method was utilized to measure the linear attenuation coefficient (LAC) for the fabricated RGN glass series for gamma-photon energies 0.662, 1.173, and 1.332 MeV emitted from 137Cs and 60Co, respectively. The accuracy of the obtained results was tested by comparing the experimental data with those simulated by MCNP-5 and those computed theoretically by XCOM. The obtained results showed agreement between the experimental measurements, simulated, and theoretical evaluations. We found that the photons with energy of 0.662 MeV have a lower penetration power. Thus, the LACs are higher at 0.662 MeV for all synthesized glass samples. The LAC values at 0.662 MeV were between 0.1849 and 0.2253 cm− 1 for the glass samples RG and RGN3. The LAC results depicted a significant relationship between the chemical composition and the synthesized glass series’ attenuation coefficients. The LAC’s measured values were enhanced with the insertion of the niobium pentoxide (Nb2O5) contents. The half-value layer (HVL, ∆0.5) was calculated for the synthesized glass series based on the measured LAC. The thinner ∆0.5 layers were achieved at 0.662 MeV and ranged between 3.077 and 3.748 cm for the glasses coded as RGN3 and RG, respectively, while the thicker ∆0.5 layers were found at 1.332 MeV and changed in the range of 4.306–4.914 cm. The influence of the Nb2O5 doping ratio was examined, and we found that the values of the ∆0.5 layers become thinner as the Nb2O5 doping ratio increases.

A comprehensive examination of zinc-boro-vanadate glass reinforced with Ag2O in physical, optical, mechanical, and radiation shielding aspects

This study explored the zinc-boro-vanadate (ZBV) glass reinforced with Ag2O to show radiation shielding competencies. A glass system with composition 20ZnO-55B2O3-(25-x)V2O5-xAg2O, where x ranges from 0 to 10 with the steps of 2.5 mol%, was designed. Some physical and optical calculations were employed to figure out glass density (ρglass), molar volume (Vm), oxygen molar volume (OMV), oxygen packing density (OPD), refractive index (n), dielectric constant (ϵ), and metalization criterion (M) for the glass system of ZBV0 to ZBV10. According to the findings, one can specify that the increasing content of Ag2O enhanced both the physical and optical features of the ZBV series. The glass density was increased from 3.3150 to 3.6930 g/cm3, while the refractive index was raised from 3.0693 to 3.1216 with the insertion ratio of Ag2O from 0 to 10 mol%. The ZBV10 sample having the maximum Ag2O of 10 mol% ensured to improve physical and optical properties. The shielding properties of the examined glass samples were investigated to evaluate their ability for radiation protection purposes. The Monte Carlo N-Particle Transport Code 5 (MCNP-5) was utilized to assess the projected gamma photons' average track length on the investigated glass samples. Then, the linear attenuation coefficient (LAC), half-value layer (HVL), transmission factor (TF), and radiation protection efficiency (RPE) were calculated based on the simulated gamma photons' average track length. The obtained results showed that the highest LAC values increased from 71.999 to 91.979 cm−1. Moreover, the thicker HVL decreased from 9.869 to 9.332 cm−1, increasing the Ag2O insertion ratio between 0 and 10 mol%, respectively. The mentioned data confirmed that substitution of the V2O5 by the Ag2O enhance the gamma-ray shielding capacity of the explored series of glass.

Influence of modifier oxide on the structural and radiation shielding features of Sm3+-doped calcium telluro-fluoroborate glass systems

A sequence of Sm3+-incorporated calcium telluro-fluoroborate glasses by changing the modifier oxide was prepared via the melt-quenching method. The physical, structural, and gamma radiation shielding properties are investigated. XRD spectra confirmed the glassy state. The glasses’ compactness was explored via the structural features like the boron-boron separation, oxygen molar volume, and oxygen packing density. Mechanical and optical properties such as Poisson’s ratio, optical electronegativity, optical basicity, two-photon absorption (TPA) coefficient, and ionic and covalent characters were evaluated and discussed per modifier concentration. The photon attenuation attributes of the glasses were computed by means of the MCNP-5 code. The mass attenuation coefficient (MAC) was simulated in the energy region of 0.015–15 MeV. The highest MAC achieved at gamma energy 0.015 MeV increased from 25.004 to 33.165 cm2g−1 with increasing the CaO ratios between 0 and 40 wt%. Besides, several attenuation factors, such as the mean free path and the radiation protection efficiency, were evaluated connected with the MAC’s simulated values. The study showed that the fabricated glasses’ radiation protection efficiency at 0.5 MeV increased from 33.39 to 39.31, increasing the CaO content from 0 to 40 mol%.

Improvement of Oxygen Mobility with the Formation of Defects in the Crystal Structure of Red Mud as an Oxygen Carrier for Chemical Looping Combustion.

Fe₂O₃ is the major component of red mud, which is a by-produced after eluting aluminum from bauxite in the Bayer process, and can be used as an oxygen carrier. On the other hand, red mud is unsuitable for using oxygen in the crystal lattice because of its low surface area. In this study the red-mud sample was sulfidated at high temperatures to improve the lattice oxygen mobility by forming lattice defects in the iron oxide crystals. To form crystal defects on red mud, iron oxide was converted to iron sulfide with hydrogen sulfide, and then re-oxidized by air to remove the sulfur components. In these processes, it was possible to generate defects could be generated in the crystal structure. Crystal defects are formed by the difference in the molar volume of oxygen and sulfur bound to the metal in the oxidation-sulfidation process. The surface area of the defective red mud increased from approximately 25.9 m₂/g to 122.1 m₂/g, and the pore volume increased from 0.1714cc/g to 0.2803 cc/g. In addition, the formation of crystal defects increased the oxygen transfer capacity of red mud from 1.75% to 2.25% at 15 vol.% hydrogen. This means that the amount of oxygen transported during the reduction process could be enhanced approximately 1.29 fold.

RETRACTED ARTICLE: Spectroscopic analysis of potassium zinc phosphate glass matrix doped CuO for optical filter applications

Phosphate glasses of chemical composition xCuO–(24-x)K2O–48P2O5–28ZnO; where x = 0, 2, 4, 6, 8 and 10 molar ratios, have been prepared using the melt quenching technique. Density, molar volume, oxygen packing density and oxygen molar volume have been calculated. Water durability is determined from the measurement of the dissolution rate in deionized water. The dissolution rate is found to decrease with increasing CuO, indicating the improvement of water durability. FTIR spectroscopy of all glass samples has been investigated in the wavenumber range 400–2000 cm−1. Analysis of FTIR spectra confirms the structural role of CuO as a network modifier. Optical spectroscopy of these phosphate glasses has been measured over the wavelength range of 190–2000 nm. By calculating the optical bandgap, it is found that Eg decrease with increasing CuO indicating the creation of non-bridging oxygens.