Y2O3 Glass Research Articles

Investigation of the Structural, Elastic, and Radiation Shielding Properties of the SiO2 –Pb3O4–ZnO –Y2O3 Glass System

Investigation of the Structural, Elastic, and Radiation Shielding Properties of the SiO2 –Pb3O4–ZnO –Y2O3 Glass System

Luminescence and Judd-Ofelt analysis of gallium aluminum gadolinium yttrium borate scintillating glass doped with Dy3+

In this work, Dy3+:B2O3–Ga2O3–Al2O3–Gd2O3–Y2O3 glasses system were prepared by melt quenching technique. The physical, chemical groups, optical, photoluminescence and radioluminescence properties of glasses were investigated. The density and refractive index tended to increase with increasing Dy2O3 concentration. The Dy3+ doped glasses absorbed photon in UV, VIS and NIR region in the absorption spectra. For photoluminescence study, the 276 and 351 nm wavelength owned the strong excitation peak, so they were used to measure the emission spectra. The main emission peak of Dy3+ showed at 487 and 575 nm with 4F9/2 → 6H15/2,13/2 transition due to both direct excitation and the Gd–Dy energy transfer. The luminescence lifetime of Dy3+ was in the milliseconds order that shortened with adding Dy2O3 content. The PL emission intensity at 100 K was around 1.48 times compared to its value at room temperature (∼300 K). The Judd-Ofelt theory was used to analyse the radiative properties of glass and its result performed the quantum efficiency around 63.75%. The X-rays induced optical luminescence represented the highest intensity in 0.50 mol% Dy2O3-doped glass similarly to the photoluminescence under 351 nm excitation. The X-rays scintillation efficiency of this glass is 14% compared with BGO crystal. The developed glass in this work owns the potential for X-rays detection material with integration mode usage, and is also interesting for white light source and laser medium applications.

Preparation and Characteristics of B2O3 – SiO2 – Bi2O3 – TiO2 – Y2O3 Glasses and Glass-Ceramics

Preparation and Characteristics of B2O3 – SiO2 – Bi2O3 – TiO2 – Y2O3 Glasses and Glass-Ceramics

Optical Properties of SiO2 – TiO2 – La2O3 – Na2O – Y2O3 Glasses and A Novel Process of Preparing the Parent Glass-Ceramics

Quaternary glasses with the composition 50SiO2 – 25TiO2 – 5La2O3 – (20-x) Na2O – xY2O3 where x : (0 ≤ x ≥ 10) were synthesized using the melt-quench technique. XRD examined the nature of prepared glasses. UV-spectroscopic of investigated glass system studied at room temperature. Both optical bandgap and refractive index of the present glass have been increased. The polarizability and basicity were determined. Thermal parameter values increased as Y2O3 increased. Under controlling heat, the glass-ceramic were prepared and confirmed using XRD. Glass-ceramics are examined using SEM to evaluate a microstructure. Ultrasonic velocities and elastic-moduli of glass-ceramic samples are increased because of the increase in internal energy. The role of Y2O3 modifier in the glass system is clearly demonstrated. Y2O3 also works as an excellent nucleating agent that can induce crystallizations, supporting in the creation of the sub-phase of glass-ceramics.

Physical, structural, optical, and radiation shielding properties of B2O3–Gd2O3–Y2O3 glass system

In the current paper, glass samples were prepared from the composition xGd2O3–(30-x)Y2O3–70B2O3 (where x = 5, 10, 15, 20 and 25 mol%) via the technique of melt-quenching. Various optical parameters and inter-atomic separation were evaluated for the fabricated samples. The results showed that the inter-substitution of Y2O3 content in replacement with Gd2O3 content in the glass matrix shows structural variation in the glass. The density increases from 3.5521 to 4.1613 g/cm3 with increase in Gd2O3 content that signifies the role of Gd2O3 being a glass modifier. The transmission spectra of the glass sample show more than 85% transmittance suggesting their superior transparency in the visible region. Also, several important shielding parameters of the prepared glass system have been computationally determined via the Geant4 model and the results were compared with Phy-X/PDS database software. The results revealed that the mass attenuation factor (µ/ρ) obtained by utilizing the two different toolkits are in agreement. The transmission fraction and the half value layer parameters of the glass system indicate that the glass sample with higher Gd concentration provides a better gamma blocking ability thanks to the high atomic number of Gd.

Non-crystallising glass sealants for SOFC: Effect of Y2O3 addition

The joining of ceramic and metal (interconnect) parts is one of the main challenges in the development of solid oxide fuel cells (SOFC). A promising approach to solving this problem is the use of glassy sealants. In this work, we investigated the effect of yttria additions on the properties of SiO2–Al2O3–CaO–Na2O–ZrO2–Y2O3 glass sealants. An increase in the concentration of yttria is shown to reduce the tendency of the glasses under study to crystallisation. A glass containing 4 wt% of Y2O3 is found to be amorphous, even after exposure at 850 °C for 100 h. Moreover, the defectiveness of the glass microstructure, after sealing, is found to decrease along with a growth in the Y2O3 concentration. The developed non-crystallising sealant was successfully applied for joining a YSZ ceramic and an Fe–Ni–Co alloy having the phase transition of around 500 °C. The use of the non-crystallising sealant allows us to join materials with very different thermal expansion coefficients and to avoid cracking under cooling, which might occur due to a large difference in thermal expansion coefficients.

Plasma resistance of quartz with a glass coating layer by aerosol deposition

ABSTRACTTo improve the plasma resistance behaviour, glass frits of SiO2–Al2O3–Y2O3 with various powder sizes were coated onto quartz substrates by the aerosol deposition (AD) method. The thickness and microstructure of the coating layers were observed using a surface profiler and scanning electron microscopy. Plasma resistance was measured via the quartz substrate, after exposure to an inductively coupled plasma etcher. The coating layers were densely formed on the quartz substrates without additional heat treatment, and the layer thickness changed for the glass frit size distribution and AD process conditions. The SiO2–Al2O3–Y2O3 glass coating layer showed a higher plasma resistance than quartz. Furthermore, the AD coating layer was evenly etched after plasma exposure. This study improves the lifetime of plasma chamber components in the semiconductor industry.

Supercontinuum generation from 437 to 2850 nm in a tapered fluorotellurite microstructured fiber

We demonstrated supercontinuum (SC) generation in a tapered fluorotellurite microstructured fiber (MF) with a sub-micrometer core diameter. Fluorotellurite MFs based on TeO2–BaF2–Y2O3 glasses were fabricated by using a rod-in-tube method and a tapered fluorotellurite MF with a minimum core diameter of ~0.65 µm was prepared by employing a tapering system. A 1560 nm femtosecond fiber laser was used as the pumping source. With increasing the peak power of the launched pump laser to ~11 kW, SC light expanding from 437 to 2850 nm was generated in the tapered fluorotellurite MF. In addition, relatively strong blue-shifted dispersive wave at ~489 nm was also observed from the tapered fluorotellurite MF.

2.074- Lasing From Ho3+-Doped Fluorotellurite Microstructured Fibers Pumped by a 1120-nm Laser

We demonstrate 2.074- $\mu \text{m}$ lasing from Ho3+-doped fluorotellurite microstructured fibers (FTMFs) pumped by a 1120-nm Yb3+-doped fiber laser. Ho3+-doped FTMFs based on TeO2–BaF2–Y2O3 glasses are fabricated by using a rod-in-tube method. With increasing the pump power to 253 mW, lasing at 2.074 $\mu \text{m}$ is achieved from a 42-cm-long Ho3+-doped FTMF. With further increasing the pump power to 1015 mW, a maximum unsaturated power of 98 mW is obtained, and the corresponding slope efficiency is up to 12.4%. In addition, relatively strong 1.2- and 2.9- $\mu \text{m}$ emissions are also observed from the Ho3+-doped FTMF.

Crystallisation studies of Si3N4–Al2O3–SiO2–Y2O3 glass–ceramics under different heat-treatment conditions

The effects of different heat-treatment temperatures and gases on the crystallisation of Si3N4–Al2O3–SiO2–Y2O3 glasses were investigated. Simultaneous thermal analyses and high temperature calorimetry were carried out to determine the glass transition temperatures, the crystallisation temperatures and enthalpies. In situ high temperature X-ray powder diffraction was used to determine the crystallisation behaviour of these glasses while X-ray diffraction studies were carried out to find the volume fraction of phases. The qualitative and quantitative phase analyses were conducted using scanning electron microscopy combined with energy dispersive analysis and electron microprobe. It was found that the gas type, the ageing temperature and the nitrogen content were greatly affecting the microstructure and the glass transition temperatures in Si3N4–Al2O3–SiO2–Y2O3 glass–ceramics and produced different modifications of yttrium disilicate. Moreover, it was observed that the formation of D-phase (YSi2AlO4N2) depends on the initial nitrogen contents in the samples.

Characterization of thermal conductivity of SiO2–Al2O3–Y2O3 glasses

The thermal properties of SiO2–Al2O3–Y2O3 glasses were investigated within a temperature range of 25–800°C. This found that glass with a composition of 24Y2O3·21Al2O3·55SiO2 exhibits a thermal conductivity of 1.04W/mK at room temperature, and thermal conductivity increases with temperature due to an increase in the amount of bridging oxygen. The thermal conductivity of glasses with a composition of xY2O3·21Al2O3·(79-x)SiO2, on the other hand, decreased with an increase in either the Y2O3 content or Al2O3/SiO2 ratio. This decrease in thermal conductivity was analyzed with respect to the decrease in phonon mean free path resulting from the increased non-bridging oxygen content, which revealed 24Y2O3·21Al2O3·55SiO2 to have the maximum thermal conductivity of 1.7W/mK at 800°C. Glass systems incorporating yttria can therefore be considered suitable sintering additives for highly thermally conducting ceramics such as silicon nitride.

Optical and mechanical properties of amorphous bulk and eutectic ceramics in the HfO2–Al2O3–Y2O3 system

Bulk glasses containing HfO2 nano-crystallites of 20–50nm were prepared by hot-pressing of HfO2–Al2O3–Y2O3 glass microspheres at 915°C for 10min. By annealing at temperatures below 1200°C, the bulk glasses were converted into transparent glass-ceramics with HfO2 nano-crystallites of 100–200nm, which showed the maximum transmittance of ∼70% in the infrared region. An increase of annealing temperature (>1300°C) resulted in opaque YAG/HfO2/Al2O3 eutectic ceramics. The eutectic ceramics contained fine Al2O3 crystallites and showed a high hardness of 19.8GPa. The fracture toughness of the eutectic ceramics increased with increasing annealing temperature, and reached the maximum of 4.0MPam1/2.

Preparation and Optical Property of Glass Ceramics Containing Ruby Crystals

We have developed the glass ceramics containing ruby crystals by heat treatment of a Cr3+‐doped SiO2–Al2O3–Y2O3 glass at 1550°C. The shape of precipitated crystals in the glass matrix was rod type whose average width and length were around 10 and 200 μm, respectively. From an X‐ray diffraction measurement and an electron probe X‐ray microanalysis, it was confirmed that the rod crystals were α‐Al2O3. Intense emission bands of Cr3+ at 694 nm, called the R‐lines, were observed in the glass ceramics heat treated above 1300°C. In addition, the intense red luminescence was observed only in the α‐Al2O3 rod crystals by a photoluminescence mapping image.

Near infrared broadband emission from Bi5+-doped Al2O3–GeO2–X (X=Na2O,BaO,Y2O3) glasses

The authors report on near infrared broadband emission with a wavelength ranging from O to S telecommunication bands in Bi5+-doped GeO2–Al2O3–Na2O, GeO2–Al2O3–BaO, and GeO2–Al2O3–Y2O3 glasses. The superbroadband character is ascribed to the emission of Bi5+ ions. The differences among the optical characters of the glasses are due to the Bi5+ affected by the introduction of yttrium and barium. As the integration of yttrium and barium into GeO2–Al2O3–Bi2O3 system would offer a preferable environment for the formation of Bi5+, the integration of yttrium and barium leads to the redshift of absorption edges as well as the accentuation of Bi5+ concentration.

Spherical Yttrium Aluminum Garnet Embedded in a Glass Matrix

Containerless processing was used to investigate the glass‐forming behavior of Al2O3–Y2O3 glass. The amorphous bulk samples were obtained at compositions with 25–37.5 mol% yttria when the melt was cooled at a cooling rate of ∼250 K/s. Although small spherical particles (∼10 μm) with the same composition of the matrix were detected in the amorphous samples with 32.5–37.5 mol% yttria, the microfocus X‐ray diffraction result indicated that the small spherical particles were crystalline Y3Al5O12 garnet (YAG), rather than being amorphous. This observation suggested that small YAG particles could not grow larger after their nucleation, because of the high viscosity at high undercooling and the high cooling rate, which would graze the nose of the continuous cooling temperature diagram of YAG.

Spectroscopic Properties and Thermal Stability of Er3+‐Doped Germanotellurite Glasses for Broadband Fiber Amplifiers

The thermal stability and spectroscopic properties of Er2O3‐doped TeO2–GeO2–ZnO–Na2O–Y2O3 glasses for 1.5 μm fiber amplifiers were investigated. The thermal stability of the 75TeO2·20ZnO· 5Na2O glass was improved by introducing GeO2 and Y2O3. The radiative transition and the nonradiative transition have a dominant influence on the 4I13/2 level lifetime of Er3+ in high‐ and low‐GeO2 regions, respectively. Adding Y2O3 increases the 4I13/2 level lifetime of Er3+ significantly. The Judd–Ofelt (J‐O) parameter Ω6 shows a strong correlation with the 1.5 μm emission bandwidth; and the larger the Ω6, the wider the bandwidth.