Lead Tellurite Glass Research Articles

Spectroscopic and Surface Wetting Properties of Samarium Doped Lead-Tellurite Glass Embedded with Titanium Nanoparticles: Self-Cleaning Glass

Spectroscopic and Surface Wetting Properties of Samarium Doped Lead-Tellurite Glass Embedded with Titanium Nanoparticles: Self-Cleaning Glass

Optical Upconversion Properties Of Tm2O3 / Yb2O3 Doped Lead Tellurite Glasses

The melt-quench process was used to create the lead-tellurite glasses codoped with lanthanides as thulium and ytterbium. Thermal characterization carried by differential scanning calorimetry. X-ray diffraction is studies to get the nature of sold sample. The UV-Visible-IR absorption spectra was carried in range of 300 nm to 1100 nm. There were four unique absorption peaks on the glass thulium –ytterbium doped glass. The frequency up-conversion (UC) fluorescence has been seen at room temperature by 975 nm excitation.

EPR, NMR, DFT and XPS study on LaAlO3 phase transition in glass and influence on glass structure and properties

Thermal treatment induced phase transition of LaAlO3 in glass and its influence on glass structure and dielectric, magnetic, and Faraday rotation properties were characterized through various techniques such as nuclear magnetic resonance, X-ray neutron diffraction, transmission electron microscopy, X-ray photoelectron microscopy, vibrating-sample magnetometer, and electron paramagnetic resonance. Cubic LaAlO3 nanocrystals were synthesized and incorporated into lead-tellurite glasses, after crystallization treatment at 380 °C for 2 h, 14-17 nm-cubic LaAlO3 nanocrystals were changed to 14-27 nm-rhombohedral LaAlO3 perovskite due to the temperature-induced viscosity and strain in the melt. The phase transition of LaAlO3 nanocrystals in glass matrix was verified through versatile techniques in terms of the octahedral AlO6 distortion, SAED patterns, changes of lattice parameters calculated by Rietveld refinement, and coordination number changes of AlO6 by NMR and XPS techniques. The modification to the glass structure was yielded by phase transition through converting TeO4→TeO3, AlO6→AlO4, BO4→BO3, and producing non-bridging oxygen. In addition, the energy band gap and density of states of glass after phase transition was calculated through Density functional theory (DFT) simulation. Glass doped with 10% LaAlO3 exhibited a promising dielectric constant and good thermal stability due to the phase transition induced polarizability, and improved optical and magnetic performance which is promising for photonics device applications.

EPR NMR, and XPS study of LaAlO3 phase transition with enhanced magnetic and Faraday rotation properties in glass-ceramics

The phase transition of LaAlO3 in heavy metal oxide lead-tellurite glass was obtained and verified, along with its influence on glass structure, magnetic, and Faraday rotation properties were characterized through various techniques such as nuclear magnetic resonance (NMR), X-ray neutron diffraction, transmission electron microscopy, X-ray photoelectron microscopy, vibrating-sample magnetometer, and electron paramagnetic resonance (EPR). Cubic LaAlO3 nanocrystals were synthesized by one-pot hydrothermal technique and doped at 1, 5, 10, and 15 mol% into glasses, respectively. The LaAlO3 nanocrystals in as-casted glasses were characterized to be around 17 nm in cubic phase belonging to the Pm3m space group. After crystallization treatment at 360 °C for 2 h, cubic LaAlO3 phases were changed to 14–27 nm-rhombohedral phases due to the temperature-induced viscosity and strain in the melt. The phase transition yielded great modification to the glass structure through converting TeO4→TeO3, AlO6→AlO4, BO4→BO3, and producing non-bridging oxygen. The LaAlO3 doping enhanced the diamagnetism of as-casted glasses, but after phase transition, the weak diamagnetic nature was changed to strong ferromagnetism and the magnetization significantly increased with the LaAlO3 doping amount (Ms =55 emu/g). The mechanism behind magnetic property enhancement was discussed through 27Al NMR and EPR of glasses. The Verdet constant of glass with 10% LaAlO3 was greatly improved to 175 rad/ T.m at 633 nm which is much higher than the documented values in the literature.

Laalo3 Phase Transition Enhanced Magnetic and Faraday Rotation Properties in Lead-Tellurite Glass

Laalo3 Phase Transition Enhanced Magnetic and Faraday Rotation Properties in Lead-Tellurite Glass

Luminescence and Judd-Ofelt study of Ho3+/Ho3+-Yb3+ doped/ codoped lead tellurite glasses for multifunctional applications

In the present study the various spectroscopic parameters of the triply ionized holmium (Ho3+) doped TeO2–Pb3O4 (TPO) glass fabricated through melting and quenching technique have been investigated by using the Judd-Ofelt (J-O) analysis. The determined higher Judd-Ofelt intensity parameter Ω2 signifies the existing covalent bonding. The transition 5S2+5F4→5I8 corresponding to the peaked energy at 18552.9 cm−1 shows the largest radiative transition probability (3315.5 s−1) and gives the confirmation for the observed strong green emission in the Upconversion (UC) study. The UC spectroscopy of the Ho3+/Yb3+ ions doped and codoped TPO glasses upon 980 nm CW laser excitation have been analyzed. The effect on the UC luminescence intensity of Ho3+: TPO glass in the presence of Yb3+ ions has been studied and the intensity enhancement processes are explored. On the basis of present investigations, the Ho3+/Yb3+ codoped TPO glass can be utilized as good optical upconverter and yellowish green display devices.

Correlation between the metallization corrosion and acetic acid in crystalline silicon photovoltaic module

This study investigates the effect of corrosion of the metallization containing lead tellurite glass frit used in solar cells due to acetic acid. When the c-Si photovoltaic (PV) module is operating in the new degradation mode, the electroluminescence (EL) dark area showed an increase in the series resistance that spreads around the bus bars. To understand metallization corrosion, a high-temperature and high-humidity test was conducted using PV modules. The metallization was observed with a scanning electron microscope. Observation of the metallization of the degraded module confirmed the generation of voids and gaps near the interface between the metallization and the Si wafer in the EL dark area. It was also observed that Te and Pb were mostly eluted from the glass frit components in the metallization during the acetic acid leaching test. The results suggest that the elution of Te by the acetic acid generates voids and gaps in the metallization.

Reduction in contact resistivity of Ag thick-film conductor on SiNx-coated Si wafer for solar cell using lead tellurite glass frit

In an application for metallization contact of Ag thick-film conductor onto the SiNx-coated Si wafer for solar cells, we examined the wettability, reactivity, microstructure, and electrical contact of two kinds of glass frits: lead borosilicate and lead tellurite. The lead tellurite frit exhibited superior wettability on Si and higher reactivity with SiNx and formed the thinner glass layer between Ag rich layer and Si for firing the Ag thick-film paste at 750 °C, resulting in better conductive contacts. The contact resistivity of Ag thick-film conductor using lead tellurite glass frit was less than one-tenth of that using lead borosilicate glass frit.

Glass waste form options for rare-earth fission products from electrochemical reprocessing

This paper describes a first-of-a-kind study where lead tellurite (Pb-Te-O), iron phosphate (Fe-P-O), and lanthanide aluminoborosilicate (LABS) glass waste forms were evaluated for treating and/or immobilizing waste streams containing high rare-earth (RE) content in different forms, e.g., RECl3, REOCl, and/or REOx. Results from this study show that NdOCl can be immobilized in 78TeO2-22PbO glass at up to 10 mass%. Higher loadings of up to 15 mass% were demonstrated, but with a small fraction of crystallization. Two Fe-P-O glasses produced from either RECl3 (RE = Nd,Ce) or NdOCl revealed products with very similar properties, demonstrating that the phosphate process can be used to dechlorinate a variety of RE-containing halide-based waste streams. The LABS glasses produced from Nd2O3 or NdOCl showed similar properties, but the LABS-NdOCl glass did have some residual Cl present. Characterization is provided for all waste forms including chemical analysis, X-ray diffraction, and bulk density.

Study on gamma-ray shielding properties of lead tellurite glass systems using PHITS

The gamma-ray shielding properties, mass attenuation coefficient, mean free path and half value layer of lead tellurite glass systems were investigated in the photon energy range of 0.015–15 MeV using particle and heavy ion transport code system (PHITS) with the use of narrow beam transmission technique. The gamma shielding efficiency of studied glass systems was compared to that of standard concretes in terms of mean free path and half value layer. The obtained results show that PHITS is very capable for investigation of radiation shielding properties to good accuracy with maximum percentage differences of less than 2% comparing to the results by XCOM database. This will make a useful alternative technique for studying radiation parameters of other glasses, for which no experimental results are available.

The influence of PbO on the radiation attenuation features of tellurite glass

Tellurite based glasses have been of considerable interest in the last decades due to their interesting mechanical, physical and chemical features. Presently, different investigators and engineers are being devoted for developing the Tellurite based glasses to be used as effective radiation shielding materials. Our aim is to study the energy as well as PbO content dependence on the gamma rays attenuation behavior of lead tellurite glasses when the PbO content changes from 0 to 30 mol% between 0.356 and 2.506 MeV photon energies. This was achieved by considering the lead tellurite glass system with the composition x(PbO)-(100-x)(TeO2). The photon attenuation factors of the lead tellurite glasses were evaluated at five energies utilizing Monte Carlo simulation (Geant4 code). The reative difference values between Geant4 and XCOM data for the six glasses are less than 7% and this validates the accuracy of the obtained results. The mass attenuation coefficient (μ/ρ) reduces with an increase in the energy whereas it increases when TeO2 is replaced by PbO. The influence of PbO on the μ/ρ is significant only at 0.356 and 0.511 MeV, but at the other energies it is found that PbO slightly affects the attenuation factor. The linear attenuation coefficient of 30PbO–70TeO2 (coded as TePb6) is higher than the other samples. The effective atomic number has the maximum value at 0.356 MeV (in the range of 27.76–41.25). We compared the mean free path for the tellurite glasses with RS-520 and RS-360, Osmani, nasir and PHP glasses. The results reveal that the lead tellurite glasses (especially the samples with high PbO content) are a candidate as protection materials from hazardous radiation and have better attenuation in comparison to some nuclear engineering materials.

The impact of Ag and Cu nanoparticles on optical and magnetic properties of new Tb2O3-PbO-TeO2 glass ceramic system

New lead tellurite glass ceramics doped with terbium (III) oxide and co-doped with AgNPs and CuNPs were obtained by melt quenching technique. The samples were analyzed by XRD, photoluminescence, UV–Vis spectroscopy and magnetic measurements. XRD data were used to estimate the nature of the obtained samples and also to determine the crystallites size. UV–Vis spectra reveal the presence of terbium ions in the batch and, for the samples co-doped with CuNPs, the presence of Cu2+ ions octahedrally surrounded by six oxygen atoms. Optical band gap energy values were calculated based on the UV–Vis data. The photoluminescence spectra exhibit the emission from terbium ions and also reveal the influence of the co-dopant nature on this emission. Magnetic measurements data show a complex behavior due the presence of Tb3+ ions, metal nanoparticles and to the microstructure of samples.

Copper nanoparticles enhanced luminescence of Eu3+ doped lead tellurite glass ceramics

Structural, optical and magnetic properties of some lead tellurite glass ceramics doped with europium(III) ions and co-doped with fixed amounts of metallic copper nanoparticles (CuNPs) or copper(II) ions (via CuO) were investigated. Samples in the (Eu2O3)x·(TeO2)80·(PbO)(19.7-x)·(CuNPs)0.3 and (Eu2O3)x·(TeO2)80·(PbO)(19.7-x)·(CuO)0.3 systems with 0 ≤ x ≤ 10 mol% were obtained and investigated for the first time. Several techniques such as X-ray diffraction, UV-VIS, EPR and luminescence spectroscopies and density and magnetic susceptibility measurements were used in order to characterize the samples. XRD data show that the samples with low Eu2O3 contents (x ≤ 1 mol%) are amorphous while for higher europium oxide contents (x > 1 mol%) are glass ceramics. They also reveal that increasing the Eu2O3 content of samples the symmetry around the europium ions changes from face centered cubic to monoclinic. These symmetry changes are confirmed by the photoluminescence data. In addition, photoluminescence data show that the co-doping with metallic copper nanoparticles enhances the emission peaks of europium ions. UV-VIS absorption spectra show the presence of six coordinated copper (II) ions located at sites with a distorted octahedral symmetry. The EPR data confirm the presence of copper (II) ions in all the studied samples. Magnetic susceptibility measurements suggest the presence of europium ions in both their 3+ and 2+ valence states and evidence an important clustering tendency of europium ions even for low Eu2O3 contents.

Structure of lead tellurite glasses and its relationship with stress-optic properties

Reverse Monte Carlo (RMC) simulations were applied for modelling the atomic structure of the PbO-TeO2 glasses containing 10, 15 and 20-mol% PbO. The short-range order of the lead-tellurium-oxygen network, involving pair correlation functions of PbO, TeO and OO pairs, the average coordination numbers and the three-particle bond-angle distributions were determined by the RMC analysis. The average PbO coordination is in the range of 5.66 ± 0.19 to 6.02 ± 0.30, whereas TeO coordination (NTe-O) decreases steadily from 3.55 ± 0.04 to 3.36 ± 0.03 with increase in PbO concentration from 10 to 20 mol%. Raman studies also confirmed that NTe-O decreases on increasing PbO concentration, the latter acts as a modifier and disrupts the local tellurite speciation. The structural parameters are used in the Zwanziger model of stress-optic response to predict that PbO-TeO2 glasses should exhibit negative stress birefringence, a result which is in agreement with the experimental findings reported in the literature.

Effects of annealing on density, glass transition temperature and structure of tellurite, silicate and borate glasses

Barium tellurite, lead tellurite, molybdenum tellurite, lead silicate and bismuth borate glasses of the compositions: xBaO-(100-x)TeO2 (x = 10, 15 and 20 mol%), xPbO-(100-x)TeO2 (x = 15 and 20 mol%), 25MoO3-75TeO2, xPbO-(100-x)SiO2 (x = 50, 60 and 65 mol%) and 40Bi2O3-60B2O3 were prepared by melt-quenching. The effects of long duration thermal annealing (below the respective glass transition temperature (Tg) values) on the density, thermal properties and the short-range structure of glasses were studied. Density increases on average by about 0.5% to 1% and Tg values show drastic increase in the range of 8 °C-64 °C after annealing. Raman and FTIR studies were performed on glasses before and after annealing, FTIR studies found that bismuth borate glasses show a small but significant increase in the fraction of tetrahedral borons in the borate network with annealing. Raman studies on lead metasilicate glass showed an increase in the concentration of SiO4 units that contain three bridging oxygens. Raman and FTIR spectra of all annealed barium and lead tellurite glasses were indistinguishable from those of the initial samples, however the FTIR spectra of annealed 25MoO3-75TeO2 glass show changes in the relative intensities of the peaks due to MoO vibrations along with the growth and sharpening of low frequency Raman bands, furthermore this glass also showed large differences in its crystallization and melting properties during thermal analysis.

Optical properties of zinc lead tellurite glasses

Abstract Tellurite glass systems in the form of [ZnO]x [(TeO2)0.7-(PbO)0.3]1-x with x = 0.15, 0.17, 0.20, 0.22 and 0.25 mol% were prepared using the melt quenching technique. XRD of the prepared samples have been measured for all samples. Both FTIR (280–4000 cm−1) and UV-Vis (200–800 nm) spectra have been measured. Optical band gap and refractive index were calculated for every glass sample. Density of glass, molar volume and oxygen packing density (OPD) were obtained. Values of the direct, indirect band gap ranged were found in the range 3.41–3.94 eV and 2.40–2.63 eV with increasing of ZnO concentration. Refractive index 2.58 and dielectric constant 6.66 were heigh at 17 ZnO mol% concentration. Molar polarizability, metallization criterion, polaron radius have been calculated for every glass composition.

Assessment of lead tellurite glass for immobilizing electrochemical salt wastes from used nuclear fuel reprocessing

This paper provides an overview of research evaluating the use of lead tellurite glass as a waste form for salt wastes from electrochemical reprocessing of used nuclear fuel. The efficacy of using lead tellurite glass to immobilize three different salt compositions was evaluated: a LiCl-Li2O oxide reduction salt containing fission products from oxide fuel, a LiCl-KCl eutectic salt containing fission products from metallic fuel, and SrCl2. Physical and chemical properties of glasses made with these salts were characterized with X-ray diffraction, bulk density measurements, differential thermal analysis, chemical durability tests, scanning and transmission electron microscopies, and energy-dispersive X-ray spectroscopy. These glasses were found to accommodate high salt concentrations and have high densities, but further development is needed to improve chemical durability.

Enhanced 1.06 μm emission in Nd3+-doped lead-tellurite glasses doped with silver nanoparticles

Increasing the emission cross section of rare earth (RE) ions-doped transparent oxide glasses is a challenging issue. The incorporation of the metal nanoparticles (NPs) has been proposed as a promising approach to improve the emission properties, though the mechanism behind such a phenomenon is a controversial topic. Tellurite glass doped with Nd 3+ ions and silver NPs is prepared and the optical absorption and emission properties are studied. The surface plasmon band of the silver NPs is observed at around 522 nm. Absorption and excitation bands of the Nd 3+ ions are detected in the visible spectral region and associated to the transitions from ground state to various excited states. Threefold enhancement in the 1.06 μ m luminescence of Nd 3+ ions is observed under 800-nm laser excitation by incorporation of AgNO 3 up to 1 mol. %. Probable energy transfer and local field enhancements are discussed to explain the possible interactions between metal and RE ions.

Structural, spectroscopic and magnetic properties of Nd3+ doped lead tellurite glass ceramics containing silver

Structural, optical, luminescent and magnetic properties of some lead tellurite glass ceramics doped with variable amounts of neodymium oxide (Nd2O3) and co-doped with fixed amounts of silver (metallic silver nanoparticles (AgNPs) and silver oxide (Ag2O)) were investigated using density, X-ray diffraction (XRD), diffuse reflectance ultraviolet-visible (DR-UV–vis) spectroscopy, photoluminescence spectroscopy (PL) and magnetic susceptibility measurements. XRD data were used to evaluate the average crystallite size and degree of crystallinity of the studied lead tellurite glass ceramics. DR-UV–vis spectra reveal the presence of Nd3+ ions in the studied samples. Both series of samples (co-doped with AgNPs or with Ag2O) exhibit negative values for the bonding parameter (δ) suggesting an ionic type of Nd3+-ligand bonds. The photoluminescence data show that for Nd2O3 concentrations higher than 1 mol% the PL peaks decrease in intensity, this concentration representing the quenching concentration. Magnetic measurement data indicate that for Nd2O3 contents lower than 3 mol% the Nd3+ ions exist as isolated species or participate to dipole-dipole interactions while for higher contents Nd3+ ions exist as species coupled by antiferromagnetic interactions.

Raman, photoluminescence and EPR spectroscopic characterization of europium(III) oxide–lead dioxide–tellurite glassy network

Raman, photoluminescence and EPR spectroscopies were used to characterize some xEu2O3·(100−x)[4TeO2·PbO2] glasses with x=0–50mol% obtained by melt quenching technique. Raman spectra of these glasses were interpreted in terms of vibration modes of deformed Te–O–Te linkages due to the intercalation of [PbOn] and [EuOn] entities produced by addition of Eu2O3 to the host lead–tellurite glass. Photoluminescence spectra of xEu2O3·(100−x)[4TeO2·PbO2] glasses reveal the presence of Pb2+, Eu2+ and Eu3+ ions. EPR data confirm the presence of Eu2+ ions in the europium–lead–tellurite glassy network and offer information about the compositional evolution of the Eu2+ ions local environment and Eu3+↔Eu2+ redox process. PL and EPR data show that the decrease of the Eu2+ ions luminescence intensity for the x≥40mol% Eu2O3 region is not due to the clusterization of europium ions but is due the decrease of the amount of Eu2+ ions as result of changes in the Eu3+→Eu2+ redox equilibrium.