Proposed Glass Composition Research Articles

Structural and spectroscopic correlation in barium-boro-tellurite glass hosts: effects of Dy2O3 doping

In this study, a series of barium-boro-tellurite glass hosts with varying concentration of Dy2O3 doping (0 to 1.25 mol%) were made by melt-quenching method. A study was conducted to investigate how Dy2O3 dopants affect the physical and spectroscopic traits of glasses. Raw materials including barium oxide (BaO), tellurium dioxide (TeO2), boron oxide (B2O3), and dysprosium oxide (Dy2O3) were used to produce these glasses. XRD patterns of the samples showed a broad hump and absence of long-range periodic lattice arrangements, indicating their amorphous nature. The Raman spectral analyses displayed the various vibration modes where the most intense band caused by BaO vibrations at 300 cm-1 and 450 cm-1 corresponding to the symmetric stretching vibration mode of Te–O–Te intra-chain bridges. The peak at 750 cm-1 was due to TeO4 and Te-O-Te vibration modes. The value of optical band gap energy was decreased from 3.155 to 2.1894 eV and then increase at higher Dy2O3 level (0.75 to 1.25 mol%). At Dy3+ contents between 0.25 to 1.25 mol% seven absorption bands were observed at 390, 424, 452, 750, 797, 895 and 1092 nm due to the electronic transitions in Dy3+. The glass refractive indices were raised from 2.3563 to 2.6584 and then decreased at higher Dy2O3 contents which was mainly because of the generation of more bridging oxygen (BO) in the glass matrix. The value of glass electronic polarizability and oxide ions polarizability calculated using LorentzLorenz equation showed a decrease with the rise of Dy2O3 contents, which was ascribed to the presence of fewer non-bridging oxygen (NBO). The optical basicity of the proposed glass hosts was calculated using Duffy and Ingram equation which was decreased with the increase of doping contents. In addition, the optical transmission was increased and reflection loss was reduced with increasing Dy+3 levels. The value of metallization parameter below 1 proved the true amorphous nature of the prepared samples. All the glasses revealed blue and yellow photoluminescence emission peaks due to 4F9/2→ 6H15/2, and 4F9/2 →6H13/2 transitions in Dy3+, respectively. The proposed glass compositions may be beneficial for the advancement of solid-state lasers.

Insights into visible luminescence and energy transfer mechanism of Eu3+/Dy3+ co-doped dolo-telluro-borate glasses

A series of Eu3+/Dy3+co-doped doro-telluro-borate (DTB) glasses were prepared using the melt-quenching approach and characterized. The absorption, excitation, emission, CIE1931 diagram and fluorescence decay profiles of these glasses were examined. The Judd-Ofelt model calculation was performed. These glasses showed prominent visible luminescence and lasing potency. The emission spectra and fluorescence lifetime decay profiles of the glasses with the increase of Dy3+ suggested an efficient energy transfer process between Eu3+ and Dy3+. The obtained chromaticity coordinates and color correlated temperature (CCT) of these glasses confirmed the emission of reddish-orange tone useful for cool white light displays. It was shown that the multicolor light emission from the studied glasses can be tuned by properly adjusting the Eu3+/Dy3+ co-doping contents. The proposed glass compositions may be advantageous for the construction of low-cost solid-state laser and cool white light emitting diodes.

Radiation shielding properties of Cd-Bi-Pb-Zn-borate glasses: influence of Bi2O3 activation

We report the detail characterizations and γ-radiation protecting characteristics of some new types of cadmium (Cd)-bismuth (Bi)-lead (Pb)-zinc (Zn)-borate glasses of the form (70-x)B2O3-10ZnO-10PbO-10CdO-xBi2O3 (with x = 0 to 20 mol%) synthesized via melt-quenching process. The influence of various Bi2O3 contents on the γ-radiation shielding traits of the obtained glass samples was evaluated by exposing them at different γ-ray energies (0.356, 0.662, 1.173, and 1.33 MeV) which were recorded by the NaI detector. XRD analyses of the as-quenched specimens showed their glassy phase. A comparison between theoretically computed (Phy-X and XCOM software) and experimentally measured various shielding parameters of the glass samples were performed. Irrespective of the Bi2O3 contents, the values of the mass attenuation coefficient, effective atomic number and effective electron density of the prepared glass samples were reduced with the increase of γ-ray energies. Furthermore, the theoretically calculated values of all the shielding parameters were agreed well with the measured ones. Regardless of the γ-ray energy exposures, the shielding capacity of the studied glasses was improved with the increase of Bi2O3 doping contents. The proposed glass compositions were asserted to be useful for the γ-ray absorber applications.

New low-temperature phosphate glasses as a host for Europium Ions

Artificial lightining, especially that of light emitting diodes, and telecommunications are penetrating every part of human lives daily. Different compositions phosphate glasses were suggested as a suitable host material for Eu3+ ions. Here rare earth metal ions act as luminescent centers also perturbing the bond order of phosphate glass network comprised of (PO4)3−, [−(O)PO3]2−, [−(O)2PO2]−, [−(O)3PO] structural units, which is indicated by Raman spectroscopy, confirming successful integration of aforementioned ions into the glass material. Glasses doped with Eu3+ ions show their typical photoluminescence spectra in low symmetry environment, consisting of the highest intensity 5D0→7F2 line. As indicated by the proceeding data, the suggested glass compositions can promisingly be employed as a low-temperature single-batch solution for the synthesis of luminescent glass matrix components, greatly reducing the energy needs compared both to silicate and borosilicate glass composites, and at the same time without the need of oxides containing expensive and heavy elements like tellurium, germanium and such. Most of the optical glass is synthesized at temperatures above 1200°C meanwhile our proposed glass compositions can be synthesized at temperatures below 1000°C which is more environmentally friendly.

Effects of bimetallic nanoparticles Ag and TiO2 embedment on tellurite zinc–silicate glass: Self-cleaning characteristics

The optimum hydrophobic activity resembling the lotus effects could be achieved by the inclusion of bimetallic nanoparticles in the tellurite–based glass. We prepared and characterized the new self–cleaning tellurite zinc–silicate glasses embedded with the silver (Ag) and Titania (TiO2) nanoparticles (NPs) via the melt-quenching method. The surface morphology, self–cleaning, mechanical and thermal properties of the as–quenched samples were determined. The embedment of bimetallic nanoparticles (AgNPs and TiO2NPs) was found to enhance the water contact angle (WCA) to transform the glass from hydrophilic (86.27º for TZSTA1 glass) to hydrophobic (97.47º for TZSTA4 glass) followed by the reconversion into hydrophilic (81.84º for TZSTA6 glass) nature. The Young, Young-Dupre, Wenzel, and Cassie–Baxter model calculations were performed to complement the experimental results. The sample TZSTA4 prepared with 0.03 mol% of AgNPs revealed the optimal WCA of 97.47º (Young), 95.47○ (Wenzel) and 130.13○ (Cassie–Baxter); surface tension value of 0.1727 Nm-1 (for Young) and 0.1761 Nm-1 (for Wenzel). It is established that by controlling the Ag and TiO2 NPs contents, the hydrophobic and hydrophilic traits of the studied glassed can be tailored, thereby enabling the proposed glass compositions suitable for diverse self-cleaning applications.

Borosilicate Radiation Shielding Glass

The results of studies of the electrophysical and thermophysical characteristics of borosilicate glass designed to attenuate electromagnetic radiation in the microwave range are presented. The compositions of glass with the minimal tendency to crystallization are determined. The effect of the chemical composition of glass on its thermophysical (temperature coefficient of linear expansion (TCLE) and heat capacity) and electrophysical (attenuation index, standing wave ratio, and dielectric loss tangent) properties is found. The proposed glass compositions can be recommended for the manufacturing of products used as shielding against radiation.

Synergistic effects of Nd3+ and Ag nanoparticles doping on spectroscopic attributes of phosphate glass

Abstract Efficient, inexpensive and eye−safe new host glass as up−conversion (UC) emission solid−state laser media became demanding. Nanoparticles (NPs) of various noble metals have been inserted into the phosphate−based amorphous host matrix to enhance the rare-earth ions (REIs) stimulated emission cross−section. Furthermore, only a few reports exist on the combined influences of neodymium ions (Nd3+) and pure silver (Ag) NPs on the structural and optical response of magnesium zinc sulfophosphate (MZSP) glasses. In this view, a series of MZSP glasses were doped by Nd3+ ions and pure Ag NPs (at different concentrations) to improve their structural and optical properties. Such melt−quench synthesized glasses were characterized at room temperature using diverse analytical measurement tools. The XRD pattern of as−quenched samples approved their amorphous nature. The FTIR and Raman spectra of glasses revealed the presence of characteristic bonding vibrations of different functional groups. The TEM images showed the existence of spherical Ag NPs (mean size of 8.34 nm) in the host glass matrix. The surface plasmon resonance (SPR) band of Ag NPs was detected around 451 nm. The UV–Vis–NIR absorption and PL emission spectra of glasses were utilized to evaluate the Judd−Ofelt (JO) intensity parameters ( Ω 2 , Ω 4 and Ω 6 ) and radiative properties. The observed fluctuation in the Ω 2 values with the increase in Ag NPs contents was attributed to the dynamic change of ligands symmetry around Nd3+ inside the glass network. Variations in the Ω 4 and Ω 6 values with the increase in Ag NPs contents indicated a considerable reduction in the glass rigidity. The PL spectra of glasses exhibited a prominent band around 576–584 nm corresponding to the 2G7/2 +4G5/2 → 4I9/2 transition in Nd3+. Glass prepared with 0.5 mol% of Ag NPs disclosed the highest PL enhancement (≈19 times) and largest emission cross−section (≈4.35 × 10−24 cm2) which was ascribed to the synergism between Ag NPs SPR mediated strong local field effect (LFE) and the subsequent energy transfer to Nd3+ appeared in the proximity of NPs. It was concluded that the proposed glass composition can lead to the development of UC solid−state laser compared to many other reported glass system.

Correlation of Optical and Mechanical Properties of Silver Nanoparticles Sensitized Europium Doped Magnesium Zinc Sulfophosphate Glasses

Magnesium-zinc-sulfophosphate glasses with various concentration of Silver nanoparticles (AgNPs) of molar composition 63.5P2O5–20MgO –15ZnSO4–1.5Eu2O3 –yAgNps (y = 0.0, 0.1, 0.3, 0.5, 0.7,0.9 and 1.1 g in excess) were prepared via melt-quenching method. As-synthesized glasses were characterized at room temperature to determine the relationship between structural and mechanical properties. Densities of glasses were increased from 3.0720 to 4.3304 g.cm-3 with increase in AgNPs embedding levels, suggesting the network shrinkages and enhanced compactness. The Young’s, shear and bulk modulus of glasses were observed to enhance with the increase in AgNPs contents. The Poisson’s ratio of the studied glasses was increased from (0.0978 to 0.1416) while the values of both Vickers hardness (from 0.0658 to 0. 0.0682 GPa) as well as (from 0.8350 to 0.8916) were increased. The proposed glass composition may be useful for the development of hard surface engineering.

Spectroscopic characteristics of Dy3+ impurities–doped borate-based glasses: Judd–Ofelt calculation

Using the melt-quenching method, Dy3+-doped lithium-strontium-zinc-borate glasses of composition 20Li2O–5SrO–5ZnO–(70-x)B2O3–xDy2O3 (0≤x≤1.25 mol%) were prepared and characterised using various tools. The Dy3+ contents dependent spectroscopic traits of these glasses were determined to identify their white light-emitting potential. The Judd-Ofelt (JO) evaluation was made to validate the experimentally measured optical properties. The XRD patterns of the as-quenched samples revealed their glassy nature and the FTIR spectra exhibited the presence of BO3 and BO4 functional groups. The absorption spectra of the samples showed twelve characteristic bands of Dy3+ wherein the hypersensitive one occurred at 1270 nm. The JO intensity parameters revealed a changing trend from Ω2>Ω4>Ω6 to Ω2>Ω6>Ω4, indicating the effectiveness of Dy3+ doping. The photoluminescence emission spectra of the glasses exhibited the three significant peaks (intense blue, intense yellow and weak red) with concentration quenching beyond 1 mol% of Dy3+. The radiative parameters of 4F9/2 → 6H13/2 transition disclosed the highest branching ratio (≥85%), radiative transition probability of 504–1711 s−1, stimulated emission cross-section from 28.70×10−22−19.01×10−22cm2, optical bandwidth of 1.34×10−20−4.63×10−20cm3 and optical gain of ~ 14.5×10−25cm2s, suggesting optical energy harnessing potential of the proposed glass composition which are useful in low threshold and efficient lasers and amplifiers design. The quantum efficiency of the glasses was ranged from 34–84%. The 1931 CIE analyses of the samples disclosed the colour coordinates appearance very close to the pure white (within 1–10%) with colour purities ranged from 11.6 to 4.8%, and the estimated values of CCT were above 5300 K, indicating their potency for the cool white light emission.

Judd−Ofelt calculations for spectroscopic characteristics of Dy3+-activated strontium magnesium borate glass

Some new type of strontium magnesium borate glass system doped with Dy3+ (various contents 0.1, 0.3, 0.5, 0.7 and 1.0 mol%) were produced using the conventional melt-quenching. Obtained glasses were thermally stable, highly transparent, and moisture resistant. As-prepared samples were characterized to determine their spectroscopic traits. The Judd-Ofelt (J-O) intensity Ωλ (λ = 2, 4, 6) and radiative parameters were calculated to validate the experimental results on the optical characteristics. The XRD pattern of the as-quenched samples verified their glassy nature, FESEM images showed uniform textures and EDX analyses detected the presence of appropriate constituents in the host matrix. Glass containing 0.7 mol% of Dy3+ revealed the optimum optical traits where the luminescence emission intensity was attenuated beyond this content. The optical gain for two intense emission transitions (4F9/2→6H15/2 and 4F9/2→6H13/2) was evaluated. The values of Ωλ (λ = 2, 4, 6) determined the ionic nature of the bonding and symmetry environment of the Dy―ligand matrix based on the viscosity and rigidity of the host glass. The 6H15/2→6F11/2 transition was hypersensitive. The ratio of the yellow to blue (Y/B) emission intensity less than unity indicated the lower degree of covalence between Dy3+ and O2− ions thereby makes these glasses effective for the near UV―LEDs. The higher values of the branching ratio (≥ 50 %) and stimulated emission cross-section enabled the proposed glass composition potential for the optical amplifiers and fibres fabrication. The resonant energy transfer and cross-relaxation processes in the Dy3+ were attributed to be responsible for the improved optical features.

Unique optical traits of Sm3+ -doped magnesium borate glass

A series of Sm3+-doped magnesium borate glasses were prepared using the melt quenching and characterized to determine the effects of various Sm3+ contents on their optical traits. The absorption and luminescence spectra of the glasses revealed ten and four significant peaks, respectively. In addition, the experimental results on the optical properties were validated using the Judd-Ofelt (J−O) analyses. The obtained J−O intensity parameters (Ωλ with λ = 2, 4, 6) confirmed the structural changes in the host network due to the Sm3+ doping. The value of Ω2 for the studied glasses indicated the covalent and asymmetric nature of the Sm3+− O2 linkages. The achieved J−O radiative parameters (quality factor, branching ratio and stimulated emission cross-section) were highest for the glass made with 0.5 mol% of Sm3+, demonstrating its lasing potency. The proposed glass compositions may be beneficial for the photonic devices.

Europium Doped Magnesium Zinc Sulfophosphate Glass as Potential Red Laser Host

Demand for rare earth ions (REIs) doped inorganic glasses have been ever-increasing for diverse photonic applications. Synthesis of these glasses needs the appropriate choice of suitable host matrices, modifiers, and REIs as dopants to improve their spectroscopic traits. In this realization, a new series of magnesium-zinc-sulfophosphate glasses were prepared with varied europium ions (Eu3+) doping contents (0 to 2.0 mol%). Such melt-quench synthesized glasses were characterized at room temperature by diverse analytical techniques to determine their physical and optical properties. XRD pattern of as-quenched samples confirmed their amorphous nature. Densities of the glass system were observed to increase from 2.540 to 2.788 g.cm−3 with the increase in Eu3+ doping contents from 0 to 2.0 mol% which were attributed to the generation of more bridging oxygen atoms and enhanced network compactness. Photoluminescence (PL) emission spectra of glasses exhibited four characteristic peaks positioned at 593, 613, 654 and 701 nm assigned to corresponding 5D0→7F0, 5D0→7F2, 5D0→7F3, and 5D0→7F4 transitions in Eu3+, in which the intensity of the peak at 613 nm (red) was highest. Emission intensities of all peaks were enhanced with the rise in Eu3+ content up to 1.5 mol% and quenched thereafter. It was affirmed that the physical and optical traits of these glass compositions can be improved by adjusting the Eu3+ doping contents. The proposed glass compositions may be potential for the development of varied photonic devices especially for eye safe solid-state red laser and fibre sensors.

On the lasing potency of samarium-activated BaSO4–TeO2–B2O3 glass host: Judd–Ofelt analysis

The quest for optimized rare earth glass host is ever-increasing. Multi-component telluro-borate glass matrices are excellent rare earth host due to their unique spectroscopic traits. Inspired by this idea, a series of (70-y)B2O3–15BaSO4–15TeO2–ySm2O3 glasses were fabricated using melt-quenching method. The measured spectroscopic features were complemented by Judd–Ofelt (JO) analysis. The absorption spectra of as-quenched samples revealed nine bands in the ultraviolet–near-infrared regions. The photoluminescence (PL) emission spectra displayed four emission channels: moderate green, orange, moderate red, and a weak red emission of Sm3+ transitions. The observed quenching in the PL intensity of the glasses prepared with y > 1.0 mol% was attributed to the binary cross-relaxation mechanisms. The calculated JO intensity parameters Ω2, Ω4, and Ω6 were ranged from 1.48 to 4.20 (× 10−20 cm2), 2.31–4.31 (× 10−20 cm2) and 1.15–1.99 (× 10−20 cm2), respectively. Moreover, the small values of Ω2 disclosed the weak covalent nature of network co-ordination in the neighborhood of Sm3+ sites. The 4G5/2 to 6H7/2 transition of Sm3+ disclosed the highest branching ratio (68.8%), emission cross section (75.90 × 10−23 cm2), gain bandwidth (167.69 × 10−29 cm3), and optical gain (172.01 × 10−26 cm2 s−1) for BSTBSm0.5 glass. Briefly, the proposed glass composition may be a potential host for visible waveguide laser application.

Europium ions and silver nanoparticles co-doped magnesium-zinc-sulfophosphate glasses: Evaluation of ligand field and Judd-Ofelt parameters

This paper reports the ligand field and Judd-Ofelt analyses of europium ions (Eu3+) and silver nanoparticles (AgNPs) activated magnesium-zinc-sulfophosphate glasses. Such glasses of composition 63.5P2O5–20MgO–15ZnSO4–1.5Eu2O3–yAgNPs (y = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.1 g in excess) were prepared via melt quenching method and characterized by different analytical tools. The feasibility of achieving a novel glass based efficient red laser and light emitting diodes (LEDs) was explored. XRD analyses of as-quenched samples verified their glassy character. UV–Vis–NIR absorption spectra of the studied glasses displayed eight peaks at 360, 380, 394, 414, 465, 531, 2091 and 2205 nm allocated to the 7F0→5L6,7F0→5G4,7F1→5L6,7F1→5D3, 7F0→5D2,7F1→5D17F6→7F0 and 7F1→7F6 transitions in the Eu3+. Observed improvement in the photoluminescence intensity associated to 5D0→7F2 transition was majorly attributed to the energy transfer among Eu3+ and AgNPs enabled localised surface plasmon resonance induced local field effects. TEM analysis confirmed the uniform dispersion and nucleation of AgNPs (average diameter ≈27.65 nm) in the glass matrix. Judd-Ofelt analyses were performed to calculate the intensity parameters (Ω2, Ω4 and Ω6) and radiative properties wherein the experimental optical data were utilized. For the studied glasses, the disclosed trend of Ω2˃Ω4 validated their ionic character and high symmetry environment around Eu3+. Proposed glass composition revealed excellent values of optical gain 2.82×10−25cm2S−1 to 20.81×10−25cm2S−1 and branching ratio (4.33–75.8%). Optimum values of critical laser parameters for 5D0→7F2 transition in MZSPEAg1.1 g glass was 20.8 × 10−25 cm2 s−1 for the optical gain and 21.1×10−22cm2 for gain bandwidth. Furthermore, the Racah parameters calculated from the first three significant visible absorption bands were reduced from 82.85×cm−1 to 72.33×cm−1 with the increase in AgNPs contents (from 0.1 to 1.1 g), signifying the weakening in f-f electrons repulsion. It was asserted that the proposed glass composition may contribute towards the development of solid-state laser and LEDs.

Waveguide laser potency of samarium doped BaSO4-TeO2-B2O3 glasses: Evaluation of structural and optical qualities

A series of samarium ions (Sm3+) doped barium-sulfur-telluro-borate glasses of composition (70-x)B2O3-15BaSO4-15TeO2-xSm2O3 (x ranged from 0.0 to 2.5 mol%) was prepared by melt-quenching method and examined via diverse analytical tools. Influence of changing Sm3+ doping contents on the structures and optical attributes of the proposed glasses was determined. The XRD pattern of as-quenched samples verified their glassy states. The FTIR spectra displayed the vibrational modes of tellurites and borates functional groups in the corresponding range of 460–850 cm−1 and 700–1650 cm−1. The EDX elemental maps confirmed the homogeneous distribution of the traced elements in the glass matrix. The UV–Vis–NIR absorption spectra of glasses exhibited nine distinct bands compatible with the transition from lower 6H5/2 state to the excited 6P3/2, 4I11/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2 and 6F1/2 states of Sm3+. The photoluminescence spectra showed four emission bands allotted to magnetic dipole 4G5/2 → 6H5/2 (moderate green at 562 nm), electric dipole dominated 4G5/2 → 6H7/2 (intense orange at 598 nm), electric dipole 4G5/2 → 6H9/2 (moderate red at 645 nm) and 4G5/2 → 6H11/2 (weak red at 703 nm) transitions in Sm3+, respectively. Glasses containing Sm2O3 contents above 1.0 mol% disclosed luminescence intensity quenching. Evaluated Judd-Ofelt intensity parameters Ω2, Ω4, and Ω6 were discerned to range from 1.48 × 10−20–4.2 × 10−20 cm2, 2.31 × 10−20–4.31 × 10−20 cm2 and 1.26 × 10−20–1.99 × 0−20 cm2 respectively. Furthermore, the lifetime of the samples decreases with increase in Sm3+ contents as unraveled by decay curve analysis. The achieved excellent spectroscopic properties of the proposed glass composition suggested their effectiveness as visible laser for waveguide applications.

Enhanced elastic and optical attributes of boro-telluro-dolomite glasses: Role of CeO2 doping

Abstract Improvement of elastic and optical properties of rare earth ions doped glasses via the amalgamation of synthetic glass formers with natural mineral modifier became a new strategy to achieve novel glass based optical devices. Inspired by this idea, we prepared some new types of CeO2 doped boro-tellurite-dolomite (BTD) glasses of composition (35-x)B2O3–30TeO2-20Dp-15Dm-xCeO2 (where 0 ≤ x ≤ 2.0 mol%, Dm: dolomite marble and Dp: dolomite pebble) by standard melt-quenching method and characterized. The role of changing CeO2 concentration on the structural, elastic and optical traits of the proposed glasses was examined. Also, direct and indirect band gap energies, Urbach energies and refractive indices of glasses were evaluated using Tauc, absorption spectrum fitting (ASF) and derivation of absorption spectrum fitting (DASF) methods. Amorphous nature of the as-quenched samples was verified from XRD pattern and SEM image showed the homogeneous disordered surface. EDX spectra disclosed the right elemental traces in the prepared glasses. The N4 ratio calculated from the FTIR spectra revealed that the inclusion of CeO2 into the BTD network indeed favoured the conversion of BO3 to BO4 structural units. Besides, the ultrasonic velocities and elastic moduli were reduced with the increase in CeO2 contents. Complete absence of any peak in the optical absorption spectra validated the existence of Ce4+ within glasses. Moreover, the absorption coefficient of prepared glasses was significantly enhanced and the absorption edge was red shifted (from 400 nm to 500 nm) with the increase in CeO2 doping. Proposed glass compositions may be beneficial for future research and development on optical filter in photonic devices.

Physical, structural, optical and photons attenuation attributes of lithium-magnesium-borate glasses: Role of Tm2O3 doping

Room temperature visible photoluminescence from rare earth ions doped in glasses became prospective for eye safe laser and sensor applications. Driven by this idea, glass system with nominal composition of 20Li2O–(70-x)B2O3–10MgO–xTm2O3 (where 0 ≤ x ≤ 1) were synthesized via a melt-quenching technique. As-quenched samples were analyzed using various analytical tools at room temperature. XRD patterns of as-quenched samples confirmed their amorphous nature and FTIR spectra revealed the existence of BO3 and BO4 structural units. Achieved glasses were transparent and thermally stable (verified by DTA curves). UV–vis-NIR spectra of glasses disclosed four significant absorption bands at round 791, 683, 466 and 355 nm which were assigned to the transitions from ground level of 3H6 to respective 3H4, 3F3, 1G4 and 1D2 excited levels of Tm3+ ions. Photoluminescence emission spectra (at an excitation wavelength of 473 nm) of prepared glasses displayed three characteristic peaks positioned at 476, 650 and 783 nm corresponding to 1G4→3H6, 1G4→3F4 and 3H4→3H6 transitions from Tm3+ ions. Also, the photon shielding properties for the LMB glasses with different Tm2O3 content were studies using the well known program (XCOM). The mass attenuation coefficients showed an increase behavior as the Tm2O3 concentration rise. Overall, the properties of LMB glasses were discerned to be sensitive to the Tm2O3 concentration variation. It was concluded that the proposed glass compositions may be useful for solid state lasers and telecommunications applications.

Specific features of glass applied for high-speed micrometallurgical casting of microwires

The present paper provides a justification for the selection of the basic composition of the system SiO2–B2O3–MgO–BaO–Na2O–K2O; its additional alloying with such elements as oxides PbO, Na2O + K2O, ZrO2 and TiO2 alters the main characteristics of glass tubes for casting microwires. The proposed glass compositions vary significantly the range of metals and alloys used to produce cast microwires in glass insulation.

Physical, structural and optical studies on magnesium borate glasses doped with dysprosium ion

Intense visible emissions from dysprosium (Dy3+) ions doped glasses became prospective for diverse technological applications. In this paper, physical, optical and structural properties of magnesium borate glasses doped with varied concentrations of Dy2O3 were examined. Such glasses were synthesised by melt quenching method and characterized at room temperature using several analytical techniques. Luminescence and absorption spectra (in the visible region) of as-quenched samples were used to evaluate the physical and optical properties. XRD pattern confims the amorphous state of as-quenched samples. The Fourier transform infrared (FTIR) spectra of glasses reveal various bonding vibrations assigned to different functional groups. UV-vis-NIR spectra disclose eight absorption bands accompanied by a band for hypersensitive transition positioned at 1260 nm (6H15/2 → 6F11/2). The values of direct and indirect optical energy band gap of the studied glasses are decreased with the increase of Dy3+ ion contents. The photoluminescence spectra of all glasses under the excitation of 380 nm display two prominent emission bands centred at 497 nm (4F9/2 → 6H15/2, blue) and 587 nm (4F9/2 → 6H13/2, green). The achieved intense luminescence from the proposed glass composition may be beneficial for solid-state laser applications.

Near-infrared up-conversion emission from erbium ions doped amorphous tellurite media: Judd-Ofelt evaluation

Efficient up-converted lasing materials are required for high performing, durable and low cost photonic devices. Rare earth ions doped glass systems with modified optical properties may meet this need. In this view, erbium (Er3+) ions doped zinc-magnesium-tellurite glass system of composition (75-x)TeO2–15ZnO–10MgO–xEr2O3 (0.5 ≤ x ≤ 2.0 mol%) was prepared via melt-quenching method. Optical behavior of such glasses was determined as a function of changing Er2O3 content to examine the feasibility of achieving up-converted lasing media. Judd-Ofelt (J-O) intensity (Ω2, Ω4, Ω6) and radiative parameters were evaluated. Glass hardness was increased linearly with increasing Er3+ ions concentration. The emission spectra revealed three peaks around 470 nm, 500 nm and 550 nm. Effect of Er2O3 content on the 4I13/2 → 4I15/2 transition was quantified in terms of fluorescence intensity and lifetime. The width of the near-infrared fluorescence band (1.53 μm) was broadened from 58.77 to 60.01 nm with the increase of Er2O3 content from 0.5 to 2.0 mol%. The proposed glass compositions were demonstrated to be potential for solid-state lasers, near infrared sensors, and other optical devices.