Doped Lithium Borate Research Articles

Transparent and lead-free Dy3+ doped lithium borate glasses for photon and neutron shielding applications

The exploration of trivalent rare-earth ion-doped lithium calcium borate glasses has surged recently due to their potential applications in solid-state lasers, medical imaging, and radiation shielding. This study focuses on transparent and lead-free Dy3+ doped lithium borate glasses for their efficacy as versatile radiation shields. Glasses with the chemical composition 50(Li2O): 20(CaO): 30−x(B2O3): x(Dy2O3) (x = 0.0, 0.1, 0.3, 0.5 and 1.0 mol% Dy2O3) were investigated. The structural changes in the lithium calcium borate glasses with Dy2O3 were investigated using Fourier transform infrared spectra of the synthesized glass samples. Experimental mass attenuation coefficients (μ/ρ) of the glasses have been determined using NaI(Tl) detector spectrometer in the energy range of 0.356–1.332 MeV. Photon interaction parameters were computed using PAGEX software in the energy range of 0.015–15 MeV. Relative dose distribution (RDD) and specific absorbed fraction of energy (SAFE) were also investigated. Additionally, macroscopic fast neutron removal cross-sections ( ΣR ) were computed to estimate neutron shielding efficiencies. The sample with 1 mol% Dy2O3(LBD1), displayed superior photon and neutron attenuation properties. Glasses with lower Dy2O3 doping concentrations (≤1 mol%) showed comparable half-value layer and effective atomic number to reference materials with higher doping concentrations. Increasing Dy2O3 doping concentration improved photon shielding parameters, with ΣR values ranging from 0.1460 to 0.1475 cm−1, higher than those of ordinary concrete, RS-360, and other reference materials. The results highlight the potential of Dy3+ doped lithium borate glasses as effective radiation shields. Further investigations on chemical combinations and Dy2O3 doping concentrations are warranted to fabricate glasses with enhanced properties.

FTIR, Raman spectroscopic, microstructure and neutron-particle interaction properties of Mo3+ doped cadmium zinc lithium-borate glasses

The application of different glass materials in the area of radiation shielding and charge particle attenuation has necessitated a comprehensive study of glass materials doped with special elements to examine the impact of the special element on the microstructure and shielding capabilities of resultant glass materials. In this study, the optical absorption spectra of Mo3+ doped cadmium zinc lithium borate glasses (BCZLMx) was investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopic methods to ascertain the suitability of BCZLMx glass microstructure to neutron and charge particle attenuation. Results show that the absorption cross-section is the dominant contributor to the total cross section for all samples, ranging from 110.9 cm−1 to 111.7 cm−1. BCZLM1 glass sample appears to be slightly more effective at removing fast neutrons from the beam while BCZLM5 glasses are effective at stopping electrons, protons, alpha particles, and carbon ions when compared to the other BCZLMx glasses samples. This implies that doping cadmium zinc lithium borate glasses with Mo3+ reduces fast and thermal neutrons shielding potential and increased charge particles interaction of the BCZLMx glass system.

Optical properties and tunable luminescence of Ce3+/Dy3+ doped lithium borate glasses for photonic applications

Optical absorption and photoluminescence properties of novel lithium borate glasses, (B2O3)-(MO)-(Li2O)–(Bi2O3) where M stands for Ca, Mg or Sr, doped with Dy and Ce ions have been investigated. The fundamental optical absorption edge of these materials is observed in the region of 315–390 nm, and depends on the nature of alkaline-earth metals used as network modifiers. The photoluminescence spectra of Dy-doped glasses reveal two intensive emission bands in the visible range, which correspond to 4F9/2→6H15/2 (486 nm) and 4F9/2→6H13/2 (580 nm) transitions of Dy3+ ions. Ce-doped glasses show one broad band in the visible range, which corresponds to the 2D →2F5/2 (340 nm) transition of Ce3+ ions. Three photoluminescence lines (980 nm, 1010 nm and 1150 nm) attributed to the Dy3+ ions electronic transitions are observed in the near-IR region of the spectrum for Dy-doped glasses, while only one at 1150 nm is observed for the Dy/Ce co-doped glasses. Peculiarities of excitation energy transfer between rare-earth activator ions are discussed. These glasses are shown to be a promising host matrix for rare-earth doping.

Tuning of smart cobalt doped borate glasses by electron beam as band-pass filters

CoO (0.2, and 0.7 wt%) doped lithium borate glass samples according to the composition of 84 % B2O3 + 12 % Li2O + 4 % Al2O3 have been prepared by melt quenching technique. Archimedes's method was used to compute the molar volumes of the formed glasses by measuring their density. For the purpose of analyzing the band-pass glass filter and UV-IR cut-off, the optical spectroscopic features of the obtained lithium borate glasses were evaluated over the entire wavelength range from 190 to 1100 nm. The effect of CoO doping ratios (0.2, and 0.7 wt%) on the optical properties of the prepared glass samples (refractive index, optical and electrical conductivity, reflection loss (RL), optical transmission (Toptical), extinction coefficient, permittivity, dielectric constants, electric susceptibility and polarizabilities) were studied. The decrease in ETauc and increase in UV–Visible cutoff range with the increase of CoO content is due to the increase of the non-bridging oxygen concentration. Co2+ ions are detected in both tetrahedral and octahedral positions in the glass matrix, according to the electron paramagnetic resonance EPR spectra. The transmittance data of the glass filters revealed that they have a broad band-pass in the Vis-NIR region. The electron beam irradiation showed an increase in the stopping range of the prepared glasses as band pass filters which makes them available for a wide-range of optical equipment including lenses and laser shields, as well as optoelectronic and photovoltaic apparatus.

Optimizing of optical and structure characters of borate glasses by different concentration of CoO: Electron beam irradiation dosimetry

Un-doped and cobalt oxide (CoO) doped lithium borate glasses with different concentrations (0.1, 0.3, and 0.5 mol %) were prepared by the conventional melting process at an approximate temperature of 1100 °C. The X-ray diffraction analysis showed the amorphous structure of the prepared glasses. Fourier transform infrared (FTIR) spectra of the synthesized glasses proved a gradual change in the glass network due to the transformation of the trigonal BO3 units into the tetrahedral BO4 units with the formation of non-bridging oxygens with the increase of CoO concentration and irradiation dose to 60 kGy. Minor changes occurred in the vibration bands of the FTIR spectra of lithium borate glasses with the increase of CoO concentration, where a slight lowering and broadening in the already existed peaks for BO3 and BO4 can be observed indicating the well dissolved of CoO in the glass matrix. The optical absorption spectra of the glasses before and after electron beam irradiation with different doses have been studied and the optical band gap, Urbach energy and refractive index also have been obtained. The results showed broad and strong absorption peaks in the visible range; these peaks can be attributed to the presence of the cobalt ions in the octahedral and tetrahedral configurations with different valence states. It is observed that the prepared glasses have a high sensitivity to electron beam irradiation which makes these glasses applicable to be used as dosimeters especially with low doses.

Blue, Red, and Green Emission from Chromium and Copper Metal Doped Lithium Borate Glass

The influence of copper metal on the structural and optical properties (absorption and emission) of the lithium borate glass samples containing chromium considered. The analysis of FTIR spectra measured, indicated the copper and chromium ions act as network former and modifier depend on the concentration of everyone in the sample content. The ratio between the BO4 groups to the total boron groups (BO4+BO3) decreases with the copper content increases up to 2 mol % and then increase. The optical properties that the Dq/B decreases with the increase the copper and higher than 2.3 which indicates the glass samples containing Cr3+ions in the high-field sites and produce conventional laser action. The emission spectra show the intensity emission bands at 440 nm, 540 nm, and 730 nm for relative strong blue, green and red bands respectively.

Iron (III) oxide doped lithium borate glasses: structural and charged particles/photon shielding properties

The elemental composition and surface morphologies of the (Li2B4O7) (100-x) - (Hematite) x glass samples (here x = 10,20, 30 and 40% weight) were acquired by SEM/EDX measurements. Using the EDX results, the mass attenuation coefficient (µ/ρ in units of cm2/g) of the glasses were generated with MCNPX simulation codes and calculated by XCOM software. Both results were matched by utilizing relative deviations. Next, Half Value Layer (HVL), Effective Atomic Number (Zeff), Mean Free Path (MFP), Exposure Buildup Factors (EBF), Energy Absorption Buildup Factors (EABF), Fast Neutron Removal Cross Sections (ΣR) and Relative Dose Distribution (RDD - for gamma and neutron) were calculated. Mass Stopping Power (MSP) and Projected Range (PR) values were calculated to examine the proton and alpha shielding properties of the hematite doped glass samples. According to the results obtained, µ/ρ, Zeff, and ΣR values increase as the percentage of hematite mineral in the glass samples increases. In addition, it was observed that HVL, MFP, EBF, EABF and RDD values decreased with increasing hematite percentage. The increase in the rate of hematite in the glass provided alpha and proton particles to have shorter ranges. Among the studied glass samples, lithium borate glass with 40% hematite mineral ratio is the sample with the best gamma, neutron and charged particles shielding features.

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.

Gamma ray shielding capacity and build up factors of CdO doped lithium borate glasses: theoretical and simulation study

The ability of six cadmium doped alkali borate glasses was evaluated to be used for shielding application. Monte Carlo simulation code (MCNP-5) used to simulate the shielding parameters for gamma ray in energy zone increase from 0.015 to 15 MeV. The mass attenuation coefficient (MAC) of the studied glasses was found to enhance with replacement of Li2O with CdO contents. The higher MAC was found to increase from 1.652 to 7.453 cm2.g-1 for glasses BLNC0 without CdO content and BLNC10 with Coda 10 mol%. Moreover, the thicker half value layer was found to vary decrease from 18.201 to 12.144 cm and the higher mean free path was found to decrease from 26.259 to 17.521 cm for glasses BLNC0 and BLNC10 respectively. The effective atomic number (Zeff) for the investigated glasses was also estimated theoretically and the results showed enhancement of the Zeffwith insertion of CdO contents. The exposure buildup factors (EBF and EABF) were also calculated in the energy range between 0.015 and 15 MeV. Other pivotal, the removal cross section (ΣR) for fast neutron was also calculated for the investigated glasses. The obtained results showed a significant variation in the ΣR with the increase of CdO contents in the studied glasses.

Optical, structural and gamma ray shielding properties of dolomite doped lithium borate glasses for radiation shielding applications

The elemental analysis of dolomite [CaMg(CO3)] doped glasses encoded DG10, DG20, DG30 and DG40 with different compositions is tested using Energy Dispersive X-ray (EDX) technique. Next, the surface morphology of fabricated glasses was investigated with scanning electron microscopy (SEM). On the other hand, the optical properties of fabricated the Dolomite additive were evaluated along the wavelength ranged from 300 to 900 nm. At last, nuclear radiation shielding properties of dolomite glasses were determined for gamma-rays. It is observed from the optical absorption spectra that the surface becomes smooth with no agglomerations with Dolomite%30 and %40. In addition, the results showed that Dolomite additive improves the gamma protecting capacity of lithium borate glasses. As a result, it can be referred that a glass sample with the highest Dolomite additive encoded DG40 has better shielding efficiency in terms of radiation shielding.

Structural and spectroscopic properties of Er3+ doped sodium lithium borate glasses.

The trivalent erbium (Er3+) doped sodium lithium borate glass with composition (65-x)B2O3-15Na2O-10PbO-5ZnO-5Li2O-xEr2O3 have been successfully fabricated by melt-quench technique. The structural properties were investigated by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR). The absorption and luminescence spectra of glass samples were measured to determine the spectroscopic properties. The Judd-Ofelt parameters were calculated based on absorption spectra with values of Ω2, = 4.39, Ω4 = 3.22, and Ω6 = 0.91 (×10-22 cm2) for 2.0 mol% Er3+ ion doped sodium lithium borate glass. Furthermore, radiative properties including effective bandwidth (Δλeff), radiative transition probability (AR), radiative lifetime (τR), and branching ratio (βR) were also calculated and analyzed. A strong emission band at 1532 nm was observed corresponding to 4I15/2 → 4I13/2 transition under the excitation wavelength of 528 and 976 nm. The stimulated emission cross-section (σe) and figure of merit (FWHM xσe) were calculated and compared with other glasses in order to evaluate the properties of the present samples for optical amplifier. Based on the characterization results, we found that the glass with 2.0 mol% Er3+ ion doped sodium lithium borate glass had the highest stimulated emission cross section compared to other samples and were comparable with the previous reports.

Dazzling red luminescence dynamics of Eu3+ doped lithium borate glasses for photonic applications

A series of distinct concentrations of Eu3+ doped lithium borate glassy matrices were prepared by melt quenching technique and their structural and luminescence characteristics have been studied. A wide hump exhibited in X-ray diffraction spectrum and smooth surface from SEM analysis affirms the nebulous behavior of the obtained glassy matrices. A strong excitation band noticed at 393 nm (7F0→5L6) correlated with the excitation wavelength of near-UV LED chip. By exciting with 393 nm, photoluminescence spectra reveals a strong red emission at 612 nm (5D0→7F2). Luminescence intensity has been embellished remarkably with rising Eu3+ concentration up to 1.0 mol % which can be identified as optimized concentration. At higher concentrations of Eu3+, emission intensity has been decreased due to concentration quenching. The excited level 5D0 lifetime is computed and it is evaluated to be 2.57 ms from the decay profile of 1.0 mol % Eu3+: LBZ glassy matrix. CIE color coordinates have been calculated from the luminescence spectra, which indicates strong red emission. Based on the luminescence spectral features, 1.0 mol % Eu3+: LBZ glassy matrices could be suggested as favorable candidates for the application of reddish orange emission photonic devices.

Improved thermoluminescence and kinetic parameters of new strontium/copper co-doped lithium borate glass system

We report the modified thermoluminescence (TL) response of a new melt-quench synthesized strontium (Sr) doped lithium borate (LBSr) glass system co-doped with copper (Cu). Both Sr (0.5–2.5 mol%) and Cu (0.005–0.1 mol%) concentrations are varied to determine the optimum TL properties by exposing them to 6 and 10 MeV electrons irradiations. A single broad TL peak with the maximum peak temperature around 180–220 °C is evidenced. Glass sample with 2 mol% of Sr and 0.01 mol% of Cu content revealed the optimum TL response in addition to superior linearity in the dose range of 0.5–4 Gy. The dose dependent minimum detectable dose, fading, and reproducibility are determined. Samples displayed higher sensitivity to 10 MeV electron irradiations than to 6 MeV. Furthermore, this new composition showed easy annealing, excellent reproducibility, minimal fading and obeyed second order kinetics. These attractive features make the achieved glass system prospective for radiation dosimeter fabrication.

Structural and nuclear radiation shielding properties of bauxite ore doped lithium borate glasses: Experimental and Monte Carlo study

In this work, (Li2B4O7)(100-x) (Bauxite)x (x = 0,10, 20, 30 and 40%) glasses were fabricated by standard melt quenching method. XRD spectra of the glasses were acquired and amorphous structures were verified. The variation of density and molar volume of the bauxite ore doped glasses were examined. The mass attenuation coefficients were measured for 81, 276, 302, 356 and 383 keV of incident photon energies by utilizing transmission method, MCNPX code and WinXCOM program. The obtained results are in good agreement with each other. Other gamma-ray shielding parameters such as half value layer (HVL), and effective atomic number (Zeff) for the bauxite doped glasses were also calculated. Additionally, neutron transmission factors and neutron removal cross-sections of the produced glasses were also investigated to interpret the neutron absorption capabilities. It was observed that the obtained parameters changed according to the increasing bauxite percentage of the lithium borate glasses. 40% bauxite doped glass showed the superior gamma and neutron shielding features. The presence of Fe, Ti and Al elements in the Bauxite mine has improved the shielding properties of lithium borate glasses.

Luminescent, semiconducting, thermal, and structural performance of Ho3+-doped lithium borate glasses with CaF2 or MgF2

Multicomponent lithium borate glasses containing either CaF2 or MgF2 and doped with 0.125 → 0.5% Ho2O3 replacing Li2O were prepared by the melting and annealing technique. The optical, FTIR, photoluminescence spectral and thermal properties of the prepared glasses were examined. The glasses were subjected to the controlled heat treatment two-step regime to be converted to their corresponding glass–ceramics. X-ray diffraction studies indicate the separation of different crystalline phases upon heat treatment in accordance with the presence of either CaF2 or MgF2. The optical spectral measurements of the two undoped glasses show a prominent UV absorption which is due to unavoidable contaminated trace iron impurities, while Ho2O3-doped glasses show additional extended visible–near IR absorption peaks which are related to absorption of Ho3+ ions. Structural FTIR measurements indicate the appearance of nearly similar condensed vibrational bands within the range 400–1600 cm−1 which are correlated with the presence of both triangular and tetrahedral borate groups within their distinct varying wavenumbers. The IR spectra of the glass–ceramic derivatives resemble to a large extent that for their parent glasses with minor variations. The photoluminescence (PL) spectra reveal four distinct excitation peaks within the range 365 → 453 nm and two emission peaks at about 480 and 575 nm. The glass–ceramics PL spectra show minor variations. The thermal expansion curves of the selected undoped and high 0.5 Ho2O3-doped glass from the two studied series show comparable thermal parameters revealing some variations within the thermal data in accordance with the suggested different housing behaviors of constitutional MgF2 or CaF2. The calculated optical parameters data involving the optical bandgap, Urbach energy, and refractive index are assumed to be correlated with the constitutional network structure of glass and its change with variations in the glass composition or percent of dopant oxide.

Influence of alkaline earth oxides on Eu3+ doped lithium borate glasses for photonic, laser and radiation detection material applications

50Li2O - 20MO - (30-x)B2O3 - xEu3O3 where (M = Mg, Ca, Sr, Ba) and (x = 0, 0.1, 0.3, 0.5, 1.0, 3.0, 5.0, 7.0 glasses were prepared and characterized to study their physical & optical properties using spectroscopic measurements such as UV-Visible spectra, Luminescence spectra, Radio-Luminescence, X-Ray Luminescence etc. The electronic transitions in the UV-VIS and NIR regions are assigned to the 7F0 → 5L6, 7F0 → 5D2, 7F0 → 5D1, 7F0 → 7F6 and 7F1 → 7F6 levels centered at 394, 465, 532, 2092 and 2202 nm due to their transitions from 7F0 ground state to various excited states of Eu3+ ions, respectively. Structural studies were analyzed using Raman Spectra. Five transition bands of luminescence spectra have been observed by using an excited wavelength of 394 nm. With five emission transitions of 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 as was reported previously in literature at 578, 591, 591, 614, 653 and 702 nm, respectively. The lower phonon energy (∼971 cm−1) and higher phonon side band intensity is observed at 5.0 mol% Eu2O3 content doped LBaB glasses while higher phonon energy (∼1176 cm−1) and lower phonon intensity observed for 5.0 mol% Eu2O3 content doped LMgB glasses. The chromaticity coordinates of Eu3+ ions in all LiMOB glasses falls in the reddish orange region. The radioluminescence (RL), emission spectra were corresponding to those from PL measurements. From RL measurement, the integral scintillation efficiency of developed glass was determined at 11.2% when compared with BGO crystal.

Tb3+, Eu3+, and Dy3+ doped lithium borate and lithium aluminoborate glass: Glass properties and photoluminescence quantum efficiency

The glass properties as well as the photoluminescence quantum efficiency of Li2O-B2O3 and Li2O-Al2O3-B2O3 glasses are investigated; both glass systems are optically-activated by the addition of the lanthanide ions Tb3+, Eu3+, and Dy3+. Glass transition, glass crystallization, and glass melting temperatures as well as glass forming temperature ranges are determined upon varying the modifier-to-former (Li2O-to-B2O3) ratio in the range between 1:6 to 1:2. For lithium borate glass, the risk of spontaneous crystallization decreases upon decreasing the lithium concentration. The photoluminescence quantum efficiency increases slightly upon decreasing the lithium concentration with the value of a Al2O3-containing sample always lower than that of the Al2O3-free correspondent.

Structural and optical properties of Dy3+-doped lithium borate glass

Structural and optical properties of Dy3+-doped lithium borate glass

Lead modified properties of molybdenum doped lithium borate glasses

The current scientific investigation deals with some significant results pertaining to the effect of substituting lead oxide on properties of lithium borate glasses having composition xPbO·(30-x)Li2O·70B2O3 + 2 mol% MoO3 (x = 0, 2, 5, 7, 10, 12 and 15 mol%, PLBM1-7). These glasses have been synthesized through appropriate melt-quench route and the non-crystalline phase formation has been confirmed through peak free X-ray diffraction measurements. Theoretical optical basicity (Λth), density (ρ) and molar volume (Vm) are observed to increase with increase in PbO content. dc conductivity has been observed to exhibit mixed electronic-ionic behaviour. DTA has been carried out to determine glass transition (Tg), crystallization (Tx) and liquidus (Tl) temperature. FTIR spectra depicted that PbO is modifying the structure of lithium borate matrix. The optical absorption spectra reveals that optical band gap (Eopt) decreases with increasing contents of PbO at the cost of Li2O.

Study on the Effect of Gamma Radiation on Some Spectroscopic and Electrical Properties of Lithium Borate Glasses

Five undoped and transition metal doped lithium borate glasses, were prepared by melting annealing method at low temperature range (650–750 °C). X-ray diffractograms confirm the amorphous natures of the prepared glasses. Some of their properties such as density, Infrared absorption spectra (FTIR) and electrical conductivity have been studied before and after being subjected to gamma radiation. Optical UV absorbance and calculations of optical energy gap have been also studied on some selected glasses. The variation in density, electrical and spectroscopic parameters was discussed in terms of both valence state and ionic radius of each doped transition metal modifier. FTIR studies demonstrate that these glasses consist of BO3 and BO4 constructing groups with an obvious increase in their IR band intensities after irradiation with 20 kGy. The electrical properties of glasses were studied under the effect of both gamma radiation and temperature range from 298 to 473 K. A significant variation in electrical conductivity values was obvious when the temperature exceeds 413 K in the dose range from 5 to 20 kGy of gamma radiation.