Borate Glass System Research Articles

EPR studies on VO2+doped sodium –borate glasses synthesized by microwave method

Electron paramagnetic resonance (EPR) of VO2+ions in sodium borate glass system has been studied over a wide range of composition. The EPR spectra exhibited hyper fine splitting (hfs) due to considerable weakening of interaction between vanadium ion concentrations. The hfs is seen between 10 and 35 mol% of vanadium concentration. The appearance of hfs is due to the interaction of 3d1 electron spin of 51V ion with its nuclear spin, which increases with increasing concentration till 35 mol%. The spin -Hamiltonian parameters (g and A), the dipolar hyperfine coupling parameter (P) and Fermi contact interaction parameter (k) have also been evaluated. The values of spin-Hamiltonian parameters indicate that VO2+ ions are in octahedral coordination with a tetragonal compression which can be attributed to the structural changes taking place with the increasing concentration of V2O5

Investigation of bismuth borate glass system modified with barium for structural and gamma-ray shielding properties.

In the present paper, transparent and non-toxic Bi2O3-B2O3 glasses doped with BaO have been prepared by the authors which may replace the standard radiation shielding concretes and lead based commercial glasses for gamma ray shielding applications. The effects of BaO on the structural and optical properties of the prepared glass system have been investigated by Raman, FTIR and UV-Visible techniques. It has been observed that barium plays the role of a modifier and it is responsible for conversion of triangular [BO3] units to tetrahedral [BO4] units along with formation of non-bridging oxygen and increase in ionic character. It also improves the radiation shielding abilities of the glass system. The mass attenuation coefficients for gamma-ray photons at 662 keV energy by using 137Cs radioactive source have been measured by employing narrow beam transmission geometry. This was accompanied by theoretical computation of mass attenuation coefficients in the wide photon energy range varying from 1 keV to 100 GeV. It has been found that values of mean free path and tenth value layer decrease whereas, density and effective atomic number increase with the increase of barium oxide content. As compared with barite concrete and commercial shielding glass RS-360, our prepared Bi2O3 - BaO - B2O3 glasses have shown better gamma ray shielding properties. This implies that the prepared glass system is a better gamma ray absorber and it has the potential for use in gamma-ray shielding applications.

Optical properties of bismuth borotellurite glasses doped with NdCl3

Bismuth tellurium borate glass systems in the composition of 65B2O3-12.5TeO2-12.5Bi2O3- (10-x) Na2O - xNdCl3, where x = 0, 1, 2, 5, and 10 mol% were prepared by traditional technique. XRD of the prepared samples has been measured for all samples to check the amorphous nature of the samples. Density of the studied glass samples were measured and found to increase with increasing the concentration of NdCl3 while the volume of 1 mol were estimated and found to increase till 10 mol% of NdCl3. Both FTIR (400–2000 cm−1) and UV–Vis (250–2500 nm) spectra have been measured for all studied glass samples and discussed. Tauc's and absorption spectrum fitting (ASF) methods were used to calculate both of optical band gap and refractive index for each glass sample. It is found that the values of optical band gap increased with increasing NdCl3 content and found in the range of 2.108–3.304 eV in Tauc's method, while in the range of 1.98–2.97 eV in ASF method. Refractive index values of the prepared samples decreased with increasing NdCl3 content and found in the range of 2.69 to 2.32 in Tauc's method, while in the range of 2.74 to 2.40 in ASF method.

The effect of mixed alkali on structural changes and ionic migration characteristics in zinc borate glasses

The effect of mixed alkali on structural changes and ionic migration characteristics have been investigated in zinc borate glasses system with composition 5Al2O3-15ZnO-(15-x)K2O-xNa2O-65B2O3(x = 0,3,6,9,12,15mol%). The thermal properties including glass transition temperature (Tg), thermal expansion coefficient (α) and dilatometric softening temperature (Td) were determined by differential scanning calorimeter (DSC) and dilatometer. The ionic migration characteristics were investigated through dc conductivity and chemical stability, determined by electrochemical workstation and normalized mass losses (N(i)). And the glass structure was characterized by Fourier transform infrared spectroscopy, to explain the relationship between structure and properties. As the ratio of [Na2O]/([K2O]+[Na2O])(mol/mol) increase, the glass transition temperature (Tg), dilatometric softening temperature (Td), dc conductivity(σdc) and normalized mass losses (N(i)) of glass exhibit a nonlinear variation, deviate negatively from linearity, meanwhile thermal expansion coefficient (α) varies nonlinearly and deviates positively from linearity. From the FTIR studies the N4 values (fraction of tetrahedral coordinated boron atoms) exhibit a nonlinear variation, deviates negatively from linearity. These data clearly indicated the presence of strong mixed alkali effect (MAE) in the zinc borate glass system, and the MAE changes glass structure and inhibits ion migration.

Nonradiative energy transfer and ion-ion interactions in terbium-praseodymium coactivated borate glass

A study of energy transfer between Tb3+ and Pr3+ in borate glass is being presented. From our measurement of fluorescence emission and decay times of donor (Tb3+), in the presence of different concentrations of acceptor (Pr3+), the energy transfer probability (Pda) and transfer efficiency (ɳT) have been calculated. Analyzing the data it is observed that the non-radiative energy transfer in our borate glass system occurs by dipole-dipole interactions, contrary to the observations made by Nakazawa and Shionoya (dipole-quadrupole interaction) in phosphate glass. A linear dependence of Pda versus C at low acceptor concentration suggests the migration of excitation energy among donor ions before the energy is finally transferred to the acceptor ion. At high acceptor concentrations a plot of Pdavs (C0 + C)2; where C0 is donor concentration and C is the acceptor concentration, presents a linear dependence suggesting thereby that one donor interacts with two neighbouring acceptors consistent with Fong-Diestler mechanisms of dipole-dipole energy transfer interactions.

Comparative investigations of gamma and neutron radiation shielding parameters for different borate and tellurite glass systems using WinXCom program and MCNPX code

In the present article, for different chemical compositions of B2O3‒Bi2O3, B2O3‒Sb2O3, B2O3‒WO3‒La2O3, B2O3‒MoO3‒ZnO, and TeO2‒MO (M = Mg, Ba, and Zn) glasses, by applying WinXCom program we calculated the mass attenuation coefficient (μ/ρ) values, and from these values, the effective atomic number (Zeff), electron density (Ne), mean free path (MFP), half-value layer (HVL), and exposure buildup factor (EBF) values using Geometric progression (G‒P) fitting method, including macroscopic effective removal cross-section (ΣR) values for fast neutrons are evaluated for their potential applications as γ-ray and neutron radiation shielding materials. Moreover, the μ/ρ values of all the studied different glass compositions were computed using MCNPX simulation code and compared with WinXCom results. BBi65 glass has the highest μ/ρ, and Zeff values in the B2O3‒Bi2O3 glasses and lower values of MFP, HVL, and EBF. The maximum values of μ/ρ and Zeff are recorded for BSb70 in the B2O3‒ Sb2O3 glasses. It is found that the Zeff for B2O3‒Bi2O3 glasses is higher than those for B2O3‒ Sb2O3 glasses, which reveal that the B2O3‒Bi2O3 glasses have better shielding properties than the B2O3‒Sb2O3 glasses. The μ/ρ values of B2O3‒WO3‒La2O3 glasses are higher than those B2O3‒MoO3‒ZnO glasses, which indicate that B2O3‒WO3‒La2O3 glasses show preferable radiation shielding effectiveness comparing with B2O3‒MoO3‒ZnO glasses. The variation of different shielding parameters for the selected glasses was discussed according to the three photon interactions with matter (Photoelectric effect, Compton scattering, and pair production). The calculated μ/ρ and Zeff for the selected glasses have been compared with different glasses. HVL values are compared with ordinary, hematite-serpentine, ilmenite, steel-scrap and ilmenite-limonite concretes. It is found that ΣR values for B2O3‒Bi2O3, B2O3‒Sb2O3, B2O3‒WO3‒La2O3, B2O3‒MoO3‒ZnO, and TeO2‒MO (M = Mg, Ba, and Zn) glasses lie within the range 0.1312–0.2823 cm−1, 0.0876–0.0957 cm−1, 0.1180–0.1085 cm−1, 0.1066–0.1002 cm−1, and 0.1040–0.1075 cm−1, respectively.

Gamma irradiation on bismuth borate glasses doped by Eu3+ ions: Structural, optical and mechanical investigations

The research article concentrates on the effects of gamma rays [50 kGy] over Europium doped bismuth borate glass systems based on 10ZnO-5Na2O3-10Bi2O3-(75-x)B2O3-xEu2O3 (where x = 0.1, 0.3, 0.5, 1.0, 1.5), synthesized through melt-quench technique. Structural changes in the glasses after gamma irradiation were probed by measuring the basic parameter density. XRD confirmed amorphous nature of the glasses. Optical properties were investigated for their lasing behavior through spectroscopic technique UV–vis–NIR absorption. Under mechanical characterization, Vickers (Hv) indentation tests were performed with mechanical loads 1000 gf and 500 gf. A theoretical model, Makishima and Mackenzie (M-M), gave reasonable estimation of different constants of elasticity (Young’s modulus (E), bulk modulus (K), shear modulus (S), Poisson’s ratio (μ)).

Physical and spectroscopic studies on manganese doped zinc alumino lithium borate glasses

Zinc Alumino lithium borate (ZnAlLiB) glass system containing manganese ions has been investigated by the UV-visible, Electron Paramagnetic Resonance (EPR) and Fourier Transform Infrared (FTIR) spectroscopic studies. The variation in physical parameters infers that the environment around manganese ions is different in different glasses, which leads to different structural arrangements and bonding. From optical absorption spectra, optical direct and indirect band gaps, Urbach energy values were evaluated. The EPR spectra have shown a six-line hyperfine signal centred at g ≈ 2.0 corresponding to the sites of Type II. Shift in g-value Δg reveal the ionic nature of glass systems. FTIR spectra indicate that inclusion of manganese ions are found to gradual depolymerization of MnO2–B2O3 glass matrix

Approach to dissociation energy and elastic properties of vanadate and V2O5-contained glasses from single bond strength: Part I

A systematic study has been carried out to understand changes in the structure and predict the composition dependence of elastic properties in a large number of vanadate and V2O5-contained tellurite, borate and phosphate glass systems. Both the glass dissociation energy per unit volume and packing density were estimated from the dissociation energies per unit volume and packing factors of the oxide constituents. Values of the theoretical elastic moduli and Poisson's ratio were calculated on the basis of Makishima–Mackenzie's theory and compared with the corresponding experimental values. The results reveal that, although the experimental data of Poisson's ratio appear to be predictable from the calculated packing densities, majority of the samples have values of theoretical elastic moduli much greater than the experimental ones. The disagreement between theoretical and experimental elastic moduli was discussed in terms of the basic structural units that constituting the glass network. Both the dissociation energy per unit volume and elastic moduli were evaluated in terms of the average single bond strength of V–O and P–O bonds, for the first time. A very good agreement between the theoretically calculated and experimentally measured data of elastic moduli was achieved for majority of the investigated glass samples.

Linear and nonlinear optical properties of gold nanoparticles doped borate glasses

Gold nanoparticles (NPs) embedded in sodium antimony borate glass system were fabricated and their optical, physical, structural, ultrafast nonlinear optical properties were studied and analyzed. Metallic gold NPs were synthesized using thermal reducing agent Sb2O3 and demonstrated the reduction mechanism of Au3+/Au+→Au0 by using reduction potentials of corresponding redox system. UV–Visible spectroscopy measurements have revealed the characteristic surface plasmon resonance (SPR) of Au NPs at ~565nm, attributed due to interband transition. The micrographs of High-Resolution Transmission Electron Microscopy (HR-TEM) confirmed the existence of uniformly distributed spherical shaped Au NPs with particle sizes in the 8–45nm range with an average particle size of 25nm. The ultrafast nonlinear optical properties of gold doped glasses were investigated using the Z-scan technique at a non-resonant wavelength (λ=800nm, 80MHz repetition rate) with femtosecond (fs) Ti:sapphire laser pulses. Z-scan measurements of undoped glass depicted are verse saturable absorption (RSA) type of nonlinearity whereas the gold-doped glass demonstrated saturable absorption (SA) kind of nonlinearity due to intraband (sp→sp) transitions. The Z-scan data demonstrated that the investigated glasses are potential materials for the applications in nonlinear optics devices, particularly in optical switching devices.

Optical properties of Er3+/Yb3+ co-doped bismuth calcium borate glass system for NIR lasers and fiber amplifiers

An Er3+/Yb3+ co-doped bismuthate (Bi2O3-B2O3-CaO) glass was prepared by melt quenching method. The samples were analyzed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), absorption and emission spectroscopy. The Judd-Ofelt parameters (Ωλ) were determined from the intensity of the absorption band to calculate the radiation parameters, such as the radiation lifetime (τrad), radiation transition probability (Arad) and branching ratio (βJJ′) of 4I13/2 laser conversion of Er3+ ions. The effective emission bandwidth (ΔλP), stimulated emission cross section (σse) and gain bandwidth (σse × Δλp) were determined on the emission spectra, and the optimum doping concentration of Er2O3 was 0.5mol%. The present work indicates that Er3+/Yb3+ co-doped bismuth calcium borate glass can be promising materials for solid state NIR lasers and fiber amplifiers.

Luminescence Properties of Cerium Doped Iron Calcium Boroaluminate Glass

Borate glass system of composition (100-x)B2O3-15Al2O3-20CaO-0.4Fe2O3-xCeO2 with x = 0, 0.25, 0.50, 0.75, and 1.0 mol% were prepared using conventional melt-quenching method. Optical measurements were carried out at room temperature to determine the Cerium (Ce3+) ions concentration dependent absorption and luminescence emission properties of such glass system. Optical energy band gap of the glass system were evaluated as a function of Ce3+ ions content. Indirect band gap energy was found to be lower than the direct band gap energy. Urbach energy was ranged between 0.12-0.17 eV. An increased broad absorption is observed in the UV region with increasing Ce3+ ions concentration. The emission spectra of the glass system recorded with 380 nm excitation wavelength revealed prominent cyan-green emission.

Comparative study of attenuation properties of some ternary borate glass systems

Some borate-based systems doped with sodium, zinc and lead are chosen to study gamma ray mass attenuation properties. Different parameters like mass attenuation, half value layer and mean free path have been analyzed at different photon energies. The values of molar volume have been estimated from density values to get idea regarding the compactness of the network structure. XCOM computer software has been employed to estimate mass attenuation coefficient at various energies. Further the values of HVL for the studied systems are compared with standard radiation shielding materials like concrete.

Synthesis and characterization of Dy3 + doped lithium borate glass for thermoluminescence dosimetry

Lithium borate glass systems were synthesized to study their feasibility for measuring high radiation doses using thermoluminescence (TL) technique. Lithium borate glass with a composition (mol%) of 30Li2O–70B2O3 was prepared by conventional melt quenched technique. To see the effect of Dy3+ on thermoluminescence, photoluminescence and thermal properties of the glass, 0.5wt% of Dy2O3 was added prior to the glass making. One more glass with exact lithium tetraboarte (Li2B4O7) composition doped with 0.5wt% Dy2O3 was also prepared. Thermo-physical properties like density, and glass transition did not show significant changes with addition of Dy2O3. However, optical properties like band gap, UV visible absorption and photoluminescence showed substantial changes. The optical band gap decrease from 3.05 to 2.78eV with addition of Dy2O3. Photoluminescence (PL) analysis showed a broad emission at around 475nm in all the glasses and very sharp intense emission at 570nm for Dy2O3 doped glasses. After gamma irradiation in the dose range of 0.5–5kGy the samples exhibited TL peak at around 136 and 152°C for Dy2O3 doped lithium borate and tetraborate samples, respectively. A linear dose response in TL intensity was also observed which was useful for quantitative estimation of absorbed dose.

Physical and spectroscopic studies on manganese ions in lead halo borate glasses

Lead halo borate glass systems containing manganese ions have been investigated to study the role of halide ions on the physical, optical and EPR studies. The amorphous phase of the prepared glass samples [Formula: see text]PbX2–(30[Formula: see text])PbO–69.5B2O3–0.5MnO2 with X = F, Cl and Br and [Formula: see text] mol% was confirmed from their X-ray diffraction spectra. Ionic radii of the halides played an important role in the physical properties. From the optical absorption spectra, optical band gap and Urbach energy values were evaluated. The EPR spectra have shown a six-line hyperfine (HF) structure centered at [Formula: see text] and attributed to Mn[Formula: see text] centers in octahedral symmetry. The other signals at [Formula: see text] and 4.3 were attributed to the rhombic surroundings of Mn[Formula: see text] ions. The negative shift in [Formula: see text]-value revealed highly ionic environment around the Mn[Formula: see text] ion in the glass hosts. The HF splitting constant (A), number of spins (N) and susceptibility [Formula: see text] values of the prepared glasses were also reported.

Investigation of gamma radiation shielding properties of lithium zinc bismuth borate glasses using XCOM program and MCNP5 code

In this work, we examined the usefulness of the lithium zinc bismuth borate glass systems for various radiation shielding applications and for this purpose, the mass attenuation coefficients for the glasses in the composition 50 Bi2O3–15 B2O3–(35-x) ZnO–(x) Li2O (x=0, 5, 10, 15, 20mol%) were calculated by both XCOM software and MCNP5 simulation code, respectively, within the energy range 0.015MeV–10MeV. The obtained results indicated good agreement between mass attenuation coefficient values derived from XCOM program and MCNP5 code. The obtained mass attenuation coefficients are then used to calculate the effective atomic number (Zeff), half value layer (HVL) and mean free path (MFP) for the glasses. Among the selected glasses, the glass with 35mol% ZnO was found to possess superior gamma-ray shielding effectiveness due to its higher values of both mass attenuation coefficient and effective atomic number and lower values of both HVL and MFP. The MFP values of the present glasses were compared with different glass systems and ordinary concrete. In addition, the macroscopic effective removal cross-section for fast neutron (ΣR) values was also evaluated. It is found that the ΣR values for the studied glasses lie within the range 0.1286–0.1587cm−1.

Energy transfer and colour tunability in UV light induced Tm3 +/Tb3 +/Eu3 +: ZnB glasses generating white light emission

A promising energy transfer (Tm3+→Tb3+→Eu3+) approach is brought forward to generate white light emission under ultraviolet (UV) light excitation for solid state lightening. Tm3+/Tb3+/Eu3+ ions are combinedly doped in zinc borate glass system in view of understanding energy transfer process resulting in white light emission. Zinc borate (host) glass displayed optical and luminescence properties due to formation of Zn(II)x–[O(−II)]y centres in the ZnB glass matrix. At 360nm (UV) excitation, triply doped Tm3+/Tb3+/Eu3+: ZnB glasses simultaneously shown their characteristic emission bands in blue (454nm: 1D2→3F4), green (547nm: 5D4→7F5) and red (616nm: 5D0→7F2) regions. In triple ions doped glasses, energy transfer dynamics is discussed in terms of Forster-Dexter theory, excitation & emission profiles, lifetime curves and from partial energy level diagram of three ions. The role of Tb3+ in ET from Tm3+→Eu3+ was discussed using branch model. From emission decay analysis, energy transfer probability (P) and efficiency (η) were evaluated. Colour tunability from blue to white on varying (Tb3+, Eu3+) content is demonstrated from Commission Internationale de L'Eclairage (CIE) chromaticity coordinates. Based on chromaticity coordinates, other colour related parameters like correlated colour temperature (CCT) and colour purity are also computed for the studied glass samples. An appropriate blending of such combination of rare earth ions could show better suitability as potential candidates in achieving multi-colour and warm/cold white light emission for white LEDs application in the field of solid state lightening.

Calculation of physical properties of glass via the phase diagram approach

Glass has become an indispensable and essential material with broad applications ranging from household appliances to building materials, photovoltaic cells, optical communications, and others. However, one of the major stumbling blocks to its optimal use is that the structure-property relationship has not been thoroughly characterized in the past few decades. In this paper, we present a method to predict the physical properties, including the density, refractive index, thermal expansion coefficient, elastic modulus and shear modulus, of a series of oxide and non-oxide glass systems via the phase diagram approach. The good agreement of the predicted values with experimental data shows that the phase diagram approach is useful and widely applicable for forecasting a variety of physical properties of glasses. Furthermore, compositions in the borate, germanate, and chalcogenide glass systems with anomalistic properties are carefully investigated and analyzed. Our results demonstrate that the phase diagram approach is an effective method for investigating the physical properties of glass, guiding the theoretical research and practical applications.

Luminescence features of dysprosium and phosphorus oxide co-doped lithium magnesium borate glass

Lithium magnesium borate (LMB) glass system co-doped with the oxides of dysprosium (Dy2O3) and phosphorus (P2O5) were synthesized using melt-quenching method. Prepared samples were characterized using various techniques to determine the effects of co-dopants concentration variation on their thermoluminescence (TL) and photoluminescence (PL) properties. TL glow curves of LMB:0.5Dy sample revealed a single prominent peak at Tm=190°C, where TL intensity was enhanced by a factor of 2.5 with the increase of P2O5 concentration up to 1mol%. This enhancement was accompanied by a shift in Tm towards higher temperature. Good linearity in the range of 1–100Gy with linear correlation coefficient of 0.998 was achieved. PL spectra displayed two significant peaks centred at 481nm and 573nm. These attractive luminescence features of the proposed glass system may be useful for the development of radiation dosimetry.

Spectroscopic and Radiative Properties of Several Nd3+ Ions in Borate Glass System

Radiative properties and spectroscopic studies of several Nd 3+ doped Borate glass system have been reported. Judd-Ofelt intensity parameter and other parameters like oscillator strength ( f ), effective bandwidth (D l eff ), radiative transition probabilities (A R ), stimulated emission cross section (s), branching ratio (b R ), radiative lifetime (t R ) and experimental lifetime (t exp ) for the hypersensitive Nd 3+ doped Borate Glass are listed and discussed. The variation of W 2 values for the different host matrix are expressed their covalency among Nd 3+ ions in the glass matrix. In this study, reported that the hypersensitive transition achieved at 4 I 9/2 ® 4 G 5/2 , 2 G 7/2 centered at 580 – 585 nm range.