Borate Glass Samples Research Articles

Dosimetric properties of lithium borate glass doped with dysprosium.

Characterization of thermoluminescence (TL) properties of lithium borate glass samples doped with different concentrations of dysprosium (Dy) was carried out. Samples were prepared using a melting method at 1100°C and irradiated with β-particles. The glass samples doped with 0.1% Dy displayed the best TL dosimetric properties compared with other compositions. Deconvoluted analyses of the glow curves displayed five overlapping TL glow peaks located between 392.0 and 510.3 K. A good linear TL dose-response for β-particles was obtained in the dose range 66.6 mGy to 33.3 Gy. The minimum detectible dose was evaluated to be 205.4 μGy and samples revealed thermal fading in 312 h to 29% of their original value.

Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy and nuclear radiation shielding properties of [α-Fe3+O(OH)]-doped lithium borate glasses

Goethite [α-Fe3+O(OH)]-doped lithium borate glasses in the chemical form of [(100 − x) Li2B4O7 mineral x = 10, 20, 30, 40 wt%] were synthesized and investigated in terms of their ability to protect the human being and environment from ionizing radiation. Elemental analysis of four different goethite [α-Fe3+O(OH)]-doped lithium borate glass samples called GOG10, GOG20, GOG30 and GOG40 prepared in different contribution rates was tested using energy-dispersive X-ray technique. In addition, the surface morphology of the manufactured glass samples was determined by scanning electron microscopy. The glass samples subject to the study were evaluated in terms of radiation shielding properties by calculating the shielding parameters such as mass attenuation coefficient (μm), half value layer, mean free path, effective atomic number (Zeff), exposure and energy absorption build-up factors, effective removal cross section (ΣR) for fast neutron and RDD (for gamma and neutron) with the help of the XCOM and MCNPX simulation code. Mass stopping power and projected ranges values of the studied glass samples were calculated in order to consider the shielding performance against proton and alpha particles. The results showed that increase in goethite additive increases the gamma protection capacity of glasses. As a result, the glass sample with the highest goethite contribution encoded with GOG40 has better shielding efficiency in terms of the gamma and neutron radiation shielding.

Linear/nonlinear optical parameters of niobium-free and niobium-doped bismuth borate glass samples

Glasses of (B2O3)0.6 (CaO)0.2 (Bi2O3)(0.2−x) (Nb2O5)x were prepared utilizing a fast cooling method (where x = 0.0, 0.05 and 0.10). Fourier-transform infrared spectra FTIR revealed about shapes that characterize the amorphous solids, where broad overlapping bands were observed. Incorporation of niobium pent-oxide Nb2O5 in the glass matrix caused BO3 to BO4, an increasing glasses’ molar volume and decreasing in glasses’ opacity. Some linear and nonlinear optical parameters had been explored by means of UV–visible spectra within 200–845 nm wavelength range. The absorption coefficients, Urbach energy, direct and indirect optical band gaps increased with an increase in the niobium pent-oxide concentration, and the real linear refractive index decreased. On the other side, nonlinear refractive index, first linear and third nonlinear susceptibilities were observed to increase with increase in niobium pent-oxide.

Understanding the role of post-indentation recovery on the hardness of glasses: Case of silica, borate, and borosilicate glasses

Hardness is an important property of glasses, which depends strongly on the method of measurement. Herein, we estimate the hardness of three oxide glasses, namely, pure silica (0B), borosilicate (37B), and sodium borate (75B) glass samples at micro and nanoscale. We observe that annealing of these glass samples, after polishing, has little effect on their hardness and modulus. Interestingly, we observe that the nanoindentation is unable to capture the full extent of elastic recovery, thereby underestimating the hardness of these glasses. We show that the post-indentation elastic recovery is highly dependent on the chemical composition of glass. Combining nanoindentation and atomic force microscopy (AFM) imaging, we accurately capture the complete elastic recovery of glass samples, thereby calculating the true hardness values from indentation depth profiles. Overall, we show that post-indentation elastic recovery plays a crucial role in determining the hardness of glasses.

Enhancement of nuclear radiation shielding and mechanical properties of YBiBO3 glasses using La2O3

In this study, nuclear radiation shielding and rigidity parameters of Y (0.1-x)B0.6Bi1.8O3La2x glassy system were investigated in order to determine it's suitability for use as nuclear radiation shielding materials. Therefore, a group of bismuth borate glass samples with La2O3 additive were synthesized using the technique of melt quenching. According to the results, the increase of the La2O3 additive increases the density of the glass samples and the mass attenuation coefficient (μm) values, whereas the half-value layer (HVL) and mean free path (MFP) values decrease. The effective atomic number (Zeff) is also enhanced with an increment of both mass removal cross section for neutron (∑R) and absorption neutron scattering cross section (σabs). In addition to the other parameters, rigidity parameter values were theoretically examined. The increase of La2O3 causes some other important magnitudes to increase. These are the average crosslink density, the number of bonds per unit volume, as well as the stretching force constant values of these glass samples. These results are in concordance with the increase of elastic moduli in terms of the Makishima-Mackenzie model. This model showed an increase in the rigidity of the glass samples as a function of La2O3.

Precipitation of Silver Nanoparticles in Borate Glasses by 1064 nm Nd:YAG Nanosecond Laser Pulses: Characterization and Dielectric Studies

This work aims to present a modern process to synthesis nanoparticles in a glassy matrix. Borate glasses doped by silver nitrate (AgNO3) via the melt annealing technique were irradiated by a (1064 nm wavelength) Nd:YAG (Neodymium–doped Yttrium Aluminum Garnet) laser to yeild precipitation of silver nanoparticles (AgNPs) in borate glasses. The characterization of the irradiated glasses was investigated using ultraviolet/visible (UV/Vis.), x-ray diffraction (XRD), high resolution-transmission electron microscopy (HR-TEM), field emission-scanning electron microscopy (FE-SEM), and dielectric properties. XRD patterns depict the presence of sharp diffraction peaks at 111 and 200 planes that can be attributed to the precipitated AgNPs in the borate glass sample after laser irradiation. A significant change in color was observed within the borate glass after laser irradiation, which was attributed to the appearance of surface plasmon resonance and confirmed the presence of AgNPs in the borate glass. The morphological properties and the distribution of the observed AgNPs inside the sample were performed via HR-TEM and FE-SEM. The behavior of dielectric constant and dielectric loss progressively decreased as the frequency increased. The values of AC conductivity increased as the temperature of the borate glass matrix increased.

Optical properties and gamma-shielding features of bismuth borate glasses

In the present work, six bismuth borate glass samples with chemical formula (75−x)B2O3–xBi2O3–10CaO–10Na2O–5Al2O3, (x = 0.0–25.0 mol%) have been manufactured. UV–visible spectral distributions for the investigated system were measured in the range of 250–850 nm. The optical absorption data showed the existence of allowed indirect transitions. The optical energy gap values ( $$E_{{\text{g}}}^{{{\text{opt}}.}}$$ ) via Tauc’s model vary from 3.39 to 2.45 eV. The complex dielectric constant ( $$\hat {\varepsilon }$$ ) was evaluated. All the optical parameters are found to be sensitive to the concentration of Bi2O3. Also, gamma photons’ attenuation features such as the mass attenuation coefficient (µ/ρ), gamma photon transmission function (I/Io), effective atomic number (Zeff), and half value thickness (HVT) for the investigated glass samples were estimated using MCNPX code and XCOM program in the range of 0.356–1.33 MeV. Replacement of B2O3 by Bi2O3 enhances the ability of glass samples to attenuate gamma photons. The results revealed that the studied glasses can be considered as candidate for optical fiber, devices, and gamma shieling.

Gamma Ray and FTIR Studies in Zinc Doped Lead Borate Glasses for Radiation Shielding Application

Gamma ray shielding properties of borate glass samples containing oxides of lead and zinc are prepared by melt and quench technique and evaluated theoretically using XCOM computer software for gamma ray shielding properties. However, gamma ray shielding properties are discussed in terms of various calculated parameters such as half value layer, mean free path and mass attenuation coefficient. The calculated parameters are compared by the author with conventional shielding material concrete. FTIR studies are undertaken to investigate the various structural groups present in the prepared system. Furthermore, it was observed that the glass sample S1 posses minimum HVL value and maximum mass attenuation coefficient, It has been inferred that addition of lead improve the gamma ray shielding properties and simultaneously decrease the rigidity of the glass systems due to formation of non bridging oxygen. Gamma ray shielding properties of our glass systems have been compared with standard nuclear radiation shielding concrete.

Femtosecond laser writing of photonic devices in borate glasses compositionally designed to be laser writable.

The design and performance of borate glass samples compositionally pre-designed to be femtosecond laser writable via laser-induced ion migration is reported in this Letter. It is demonstrated that borate glasses modified on purpose with small amounts of La2O3 and Na2O can be straightforwardly used to produce high-index contrast (Δn) waveguides by femtosecond-laser-assisted ion migration. The positive Δn of the waveguides is caused by the local enrichment of La2O3 in the guiding region with a slope of 8·10-3(mol.%)-1. The value of this is consistent with numerical aperture measurements of the waveguides and local compositional measurements at the guiding region performed by energy-dispersive x-ray micro-analysis. The maximum achievable Δn values can be controlled through the initial La2O3 content of the glass. Maximum Δn values >10-2 for samples with just 5.5mol. % of La2O3 have been produced. This compositional design approach could be potentially used to produce highly efficient femtosecond laser writeable glasses in other glass families.

Structural, optical, and electrical characterization of borate glasses doped with SnO2

Synthesis of borate glass matrix of composition 35Li2O–10ZnO–55B2O3 + x SnO2 wt% (x = 0.00, 0.50, 1.00, 1.50, 2.25 and 3.00) has been carried out by solid state reaction method. Nature amorphosity of these glasses was confirmed via X-ray diffraction (XRD) measurements. UV-visible absorption spectra within the 200–1100 nm wavelength range of these samples were performed. The direct/indirect optical energy gap (Egopt), Urbach energy (EU), Fermi energy (EF) were calculated. Both the optical complex dielectric constant (ε), and the optical conductivity (σopt) for the prepared glass samples were calculated by using the measured refractive index (n) and extinction coefficient (k). All the optical properties vary depending on the SnO2 content in borate glass samples. Refractive index (n) and the optical conductivity (σopt) increase with increasing SnO2 concentration. Dielectric measurements depict that both the dielectric constant (ε′) and dielectric loss (ε″) decrease with the increasing of frequency but a constant value was obtained beyond 10 kHz up to 100 kHz. However, ac conductivity (σac) increases with the increasing in frequency.

Development of Sm3+-doped Ba-Na-B glasses for orange-emitting material by investigating the effect of BaO concentration

The effect of BaO concentration contained in the barium sodium borate glass samples are focused as a main study in this research. Sm3+-doped Ba-Na-B glasses were prepared by melt-quenching technique with the chemical composition xBaO:25Na2O:(74.5-x) B2O3:0.5Sm2O3 (where x = 5, 10, 15 and 20 mol%). The highest emission light yield occurs when exciting the samples with 400 nm (corresponding to the 6H5/2→6P3/2 transition). The emission spectra of the glass samples observed with 400 nm excitation wavelength showed the emission bands centered at 562, 600 and 646 nm assigned as 4G5/2→6H5/2, 6H7/2 and 6H9/2 transitions, respectively. The color of the emitted light, calculated by emission spectra with the CIE 1931 color space of all glass samples were shown in orange. The result showed that the BaO concentration contained in glasses have the effect on the emission light yield and 10 mol% of BaO in glass was the optimum.

High and low temperature DC electrical properties of vanadium borate glasses

Semiconducting binary borate glass samples doped with vanadium of composition (H3BO3)1 + (V2O5)1-x where x ranging from 0.1, to 0.5 has been prepared by melt quench technique. The samples were annealed and their non-crystalline nature was confirmed by X-ray diffraction studies. Archimedes principle was adopted to measure room temperature density of the glass samples. High and low temperature DC electrical conductivity of the samples were analyzed and various polaron related parameters were investigated in the light of Mott’s SPH when T > and Mott’s VRH and Greaves VRH when T < (where Debye’s temperature). The investigations in these glass systems showed to be non-adiabatic electrical conduction. As per as above theories, the calculated activation energies, conductivities and various polaron parameters at different temperatures were compared. The detailed results of all the above parameters were discussed and which reveals that at high temperature regime Mott’s SPH model is adequate and at low temperature regime Greaves VRH model is valid to explain the variation of electrical conductivity of the glasses.Within the studied composition range it is for the first time the pure borate glasses doped with vanadium ions subjected to dc electrical conduction mechanism.

Optical properties of zinc borate glasses dispersed with Eu-doped SiAlON for white LED applications

Ca-α-SiAlON:Eu2+ oxynitride phosphors are typical luminescent materials with high thermal tolerances. A series of zinc borate glass samples (xZnO-(100-x)B2O3; mol%) were prepared for investigating their ability to disperse Ca-α-SiAlON:Eu2+ phosphor powders. Phosphor in glass (PiG) was prepared with SiAlON and zinc borate glass through a melting process. In the x = 45–60 range, PiGs could be obtained without the degradation of the SiAlON phosphors. The PiG composed of x = 50 glass exhibited the highest quantum efficiency. The glass structures of the mother glasses were investigated by Raman spectra; there was a decrease in the boroxol ring, and pyroborate and orthoborate were formed, on increasing x. From the XRD and SEM images, it was established that ZnAl2O4 was formed around the SiAlON powders in PiGs with x = 50, 55, and 60, respectively. This suggests that the partial crystallizations in the PiGs are effective in enhancing the photoluminescence of the SiAlON phosphors.

Influence of Nd2O3 addition on the electrical and optical properties of lithium niobium borate glass

A lithium niobium borate glass sample doped with neodymium was prepared by the quenching method. X-ray diffraction technique showed that the sample is in the glassy state and was validated by differential thermal analysis (DTA) study. From the intensities of some optical absorption bands, the Judd–Ofelt parameter Ω λ (λ = 2, 4, 6) has been evaluated. The variations in some physical properties such as the electrical conductivity, optical band gap (E g), and Urbach energy (E t ) have been correlated with structural changes in the glass sample. The shift of the cutoff towards a high wave number can be shown by the increases in band gap after annealing temperature. The nephelauxetic ratio is calculated and indicates the covalent nature of the Nd–O bond. The spectroscopic quality factor is determined and indicates that the transition 4F3/2 → 4I11/2 has the greater emission intensity.

Structural influence of mixed transition metal ions on lithium bismuth borate glasses

Lithium bismuth borate glasses containing mixed transition metals having composition 7CoO·23Li2O·20Bi2O3·50B2O3 (CLBB), 7V2O5·23Li2O·20Bi2O3·50B2O3 (VLBB) and x(2CoO·V2O5)·(30 - x)Li2O·20Bi2O3·50B2O3 (x = 0.0 (LBB) and x = 2.0, 5.0, 7.0, 10.0 mol% (CVLBB1-4)) are synthesized via melt quench route. The synthesized compositions are investigated for their physical properties using density (D) and molar volume (Vm), thermal properties by analyzing DSC/TG thermo-graphs, structural properties using IR absorption spectra in the mid-IR range and optical properties using UV–Vis–NIR spectroscopy. The Electron Paramagnetic Resonance (EPR) spectra of vanadyl and cobalt ion have been analyzed to study compositional effects on spin-Hamiltonian parameters. The non linear variations in physical properties depict a strong structural influence of Co/V- oxides on the glassy matrix. The compositional variations in characteristic temperatures (glass transition temperature Tg, glass crystallization temperature Tp and glass melting temperature Tm) reveals that Tg for glass samples CLBB is relatively less than that of pure lithium bismuth borate (LBB) glass sample wherein Tg for sample VLBB is higher than that of LBB. The increase in Tg (as compared with LBB) with an enhanced substitution of mixed transition metal oxides (2CoO·V2O5) shows a progressive structure modification of bismuth borate matrix. These predictions are very well corroborated by corresponding compositional trends of Tp and Tm. FTIR studies reveal that Co2+& VO2+ ions lead to structural rearrangements through the conversion of three-coordinated boron into four coordinated boron and thereby reducing number of non-bridging oxygen atoms. Bismuth is found to exist in [BiO6] octahedral units only, whereas boroxol rings are not present in the glass network. The theoretical values of optical basicity (Λth) and corresponding oxide ion polarizability (αo2−) have also been calculated to investigate oxygen covalency of glass matrix. Trends in both these parameters suggested an increase in ionic bonding on substitution of divalent transition metal cations causing a more bonding compaction in glass structure. The UV–Vis–NIR spectra suggest that cobalt ions exist as Co2+ states in octahedral coordination in glass network. Inter-electronic repulsion parameter and crystal field splitting energy were evaluated to understand the site symmetry around Co2+-ion in glass. X-band EPR spectra suggest that vanadium ions (V4+) exists as VO2+-ions in octahedral coordination with tetragonal compression. Spin Hamiltonian parameters g-values and A-values of VO2+ ions in glass were calculated. For sample CLBB two resonance lines in EPR spectrum attribute to octahedral symmetry around Co2+-ions were observed.

Effect of copper addition on BO4, H2O groups and optical properties of lithium lead borate glass

Lead lithium borate glass samples composition 50Li2B4O7–(50−x)Pb3O4–x CuO, where x = 0–35 mol% were prepared by melt quenching method. The density of the prepared samples was measured and molar volume was calculated. IR spectra were measured for the prepared samples at room temperature to investigate the glass structure. The IR spectra were deconvoluted using curves of Gaussian shape at approximately the same frequencies. The deconvoluted data were used to study the effect of CuO content on all the structural borate and water groups. The optical band gap obtained directly from absorption coefficient, refractive index and extinction coefficient, also by using the Tauc model. The type of transition is determined by the simple and accurate method.

Quantitative determination of copper in a glass matrix using double pulse laser induced breakdown and electron paramagnetic resonance spectroscopic techniques

A series of lithium–lead–borate glasses of a variable copper oxide loading were quantitatively analyzed in this work using two distinct spectroscopic techniques, namely double pulse laser induced breakdown spectroscopy (DP-LIBS) and electron paramagnetic resonance (EPR). DP-LIBS results measured upon a combined nanosecond lasers irradiation running at 266nm and 1064nm pulses of a collinear configuration directed to the surface of borate glass samples with a known composition. This arrangement was employed to predict the electron's temperature (Te) and density (Ne) of the excited plasma from the recorded spectra.The intensity of elements' responses using this scheme is higher than that of single-pulse laser induced breakdown spectroscopy (SP-LIBS) setup under the same experimental conditions. On the other hand, the EPR data shows typical Cu (II) EPR-signals in the borate glass system that is networked at a distorted tetragonal Borate-arrangement. The signal intensity of the Cu (II) peak at g⊥=2.0596 has been used to quantify the Cu-content accurately in the glass matrix. Both techniques produced linear calibration curves of Cu-metals in glasses with excellent linear regression coefficient (R2) values. This study establishes a good correlation between DP-LIBS analysis of glass and the results obtained using EPR spectroscopy. The proposed protocols prove the great advantage of DP-LIBS system for the detection of a trace copper on the surface of glasses.

THERMOLUMINESCENCE RESPONSE OF NANOPARTICLES GOLD DOPED LITHIUM BORATE GLASS SUBJECTED TO PHOTON IRRADIATION

The absorption coefficient of Borates glass is much closed to human body tissue. This fact makes borates as an ideal material for thermoluminescence material either for medical or environmental application. In this study, a glass system of 15% Li2CO3+ 85% H3BO3 doped with 0.1mol %nano-gold was prepared by using melt-quenching technique. Undoped and Au doped lithium borate glass samples were exposed to Co-60 gamma ray (1.25 MeV) with various doses ranging from 10 to 60 Gy by using Gammacell 220 excel. Various TL properties such as TL glow curve, linearity and sensitivity of the prepared glass were investigated. From the TL glow curve, it was found that the TL intensity increased by addition of Au into the glass system. The TL intensity of Au doped glass increases about 23 times higher than the undoped glass. The study also shows that the doped borate glass has a linear response subjected to Co-60 gamma irradiation at doses ranging from 10 to 60 Gy. The sensitivity of doped glass is about 22 times higher compared to un-doped glass

Effect of copper oxide on structure and physical properties of lithium lead borate glasses

Copper-doped Lead lithium borate glass samples with the composition of (35-x) Pb3O4–xCuO–65Li2B4O7, where x = 5, 10, 15 or 20 mol%, have been prepared by melt quenching technique. Glass-forming ability, density, electrical conductivity, magnetic susceptibility and structural properties of lead lithium borate glasses have been investigated. IR spectroscopic data show that the copper ions play the role of glass modifier. Addition of CuO influences BO3 ↔ BO4 conversion. Density is expressed in terms of the structural modifications that take place in glass matrix. The increase in Tg reflects an increase in bond strength, and samples obtain more rigid glass structure. Electrical conductivity and magnetic susceptibility χ data show a variable behavior with the increase in the copper content in two valance states Cu+ and Cu+2. In addition, optical properties depend on the change of the role of copper ions in the samples’ structure. Optical energy band gap E opt and Urbach energy E tail are determined. The increase in E opt and UV cutoff with an increase in CuO content is due to the decrease in non-bridging oxygen concentration. The decrease in E tail at higher concentrations is attributed to the copper ion accumulation in the interstitial positions and to the formation of orthoborate groups. These samples are suitable for the green light longpass filters.

Optical properties of lithium lead borate glass containing copper oxide for color filter and absorption glass

Lithium lead borate glass samples containing copper oxide are prepared using the normal melt-quenching technique. The optical constants are investigated and discussed with the substitution of $$\hbox {Pb}_{3}\hbox {O}_{4}$$ for CuO. The UV/VIS/NIR absorption spectra have been recorded at room temperature. The optical energy band gap $$\hbox {E}_{\mathrm{opt}}$$ and Urbach energy $$\hbox {E}_{\mathrm{tail}}$$ was determined. The increase of $$\hbox {E}_{\mathrm{opt}}$$ and UV cut off are due to the decrease of nonbridging oxygen concentration with increase of CuO content. The decrease of $$\hbox {E}_{\mathrm{tail}}$$ at higher concentrations is attributed to the copper ion accumulation in the interstitial positions and to the formation of orthoborate groups. Refractive index (measured and calculated), molar refraction and polarizability are correlated with the composition of the glasses. And produce a longpass filters with cutoffs in the range of 190–400 nm.