Rare Earth Doped Glasses Research Articles

Prediction of optical properties of rare-earth doped phosphate glasses using gene expression programming

The progression of optical materials and their associated applications necessitates a profound comprehension of their optical characteristics, with the Judd–Ofelt (JO) theory commonly employed for this purpose. However, the computation of JO parameters (Ω2, Ω4, Ω6) entails wide experimental and theoretical endeavors, rendering traditional calculations often impractical. To address these challenges, the correlations between JO parameters and the bulk matrix composition within a series of Rare-Earth ions doped sulfophosphate glass systems were explored in this research. In this regard, a novel soft computing technique named genetic expression programming (GEP) was employed to derive formulations for JO parameters and bulk matrix composition. The predictor variables integrated into the formulations consist of JO parameters. This investigation demonstrates the potential of GEP as a practical tool for defining functions and classifying important factors to predict JO parameters. Thus, precise characterization of such materials becomes crucial with minimal or no reliance on experimental work.

Fabrication of Tb/Eu co-doped borosilicate glasses for white-light LED and broadband photodetection

We successfully prepared a series of rare-earth doped borosilicate glasses using the melt-quenching method, and carefully investigated the luminescent properties and the spectral modulation of Tb/Eu-cdoped borosilicate glasses under UV (200–400 nm) excitation. The results show that the prepared samples have the characteristics of broadband response, excellent transparency and tunable luminescence. By adjusting the excitation wavelength, the emissions of Tb3+, Eu2+ and Eu3+ ions are observed, which exhibit yellow-green, blue, red color and multi-color even white emissions, respectively. Moreover, the energy transfer between Tb3+ and Eu3+ ions in the codoped glasses is confirmed. Tb3+ absorbs a large number of solar-blind light, transfers to Eu3+ and results in intense visible emission in a wide waveband range. This makes the Tb/Eu codoped glass a desirable candidate for solar-blind light detections. The photodetection system was built and shows a strong and stable response to the UV light of 210–400 nm. Due to broad detection range, high sensitivity and stability, our results offer strong implications for the development of photodetection device for diverse applications.

Phenomenology of M–N rule and high-field conduction in Ge–Te–Se–Sc rare-earth doped glasses

Phenomenology of M–N rule and high-field conduction in Ge–Te–Se–Sc rare-earth doped glasses

Structural characterisation of Pr3+ ions incorporated sodium lead Barium borate glasses

The Structural properties of 20Na2O – 10PbO – 10BaO –B2O3 – xPr2O3 glass doped with praseodymium have been investigated. The characterization techniques used for studying rare earth-doped glasses include energy-dispersive X-ray analysis (EDS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) for structural investigations. The concept of physical parameters plays a fundamental role in estimating the strength and structural compactness of the synthesized glass. Consequently, we investigated the influence of rare earth ions (Pr3+) concentration on physical properties. The nature and composition of the synthesized glass samples have been confirmed through Energy Dispersive X-ray Analysis (EDS) and Scanning Electron Microscopy (SEM). The results have been analyzed in view of the modified borate glass network.

Spontaneous noise of birefringence in rare-earth doped glasses

We report on first direct observation of spontaneous fluctuations of birefringence in glasses doped with rare-earth (RE) ions. The fluctuations were observed in Nd3+- and Yb3+-doped glasses as polarization noise of the laser beam transmitted through the sample in the region of the RE-ion absorption. The noise was characterized by a flat (“white”) spectrum in the range of frequencies up to 1 GHz and did not show any dependence on magnetic field. The discovered polarization noise is interpreted in terms of structural dynamics of glasses revealed at low temperatures and usually described in the model of tunneling two-level systems (TLS). High sensitivity of the polarization noise technique to this dynamics is related to small homogeneous width of f–f transitions of RE-ions in glasses and small spectral width of the probe laser light. The discovered effect provides a new experimental approach to studying low-temperature structural dynamics of different disordered matrices and interactions of impurities with environment in such media.

The effect of glass structure and local rare earth site symmetry on the optical properties of rare earth doped alkaline earth aluminosilicate glasses

The effect of glass structure and local rare earth site symmetry on the optical properties of rare earth doped alkaline earth aluminosilicate glasses

Niobium incorporation into rare-earth doped aluminophosphate glasses: Structural characterization, optical properties, and luminescence

Luminescent Rare Earth (RE3+) doped phosphate glasses with molar composition (1-x)(60P2O5 – 15ZnO – 5Al2O3 – 10BaO – 10PbO)-xNb2O5 (x = 0, 10, 20 and 30 wt%) doped with 1.0, 1.2 and 0.3 wt% of Eu2O3, Yb2O3 and Er2O3, respectively, were prepared by conventional melt cooling. The glasses were characterized by optical reflectance, Raman scattering, and multinuclear (31P, 27Al, and 93Nb) solid-state NMR spectroscopy. Monotonic 31P chemical shift changes as a function of Nb2O5 content are consistent with the successive formation of Nb-O-P linkages. Aluminum is found in four-, five-, and six-coordination, with a successive decrease in average coordination number with increasing niobium content, while 93Nb NMR indicates three distinct niobium environments in these glasses. Incorporation of Nb2O5 has the expected effects on refractive index values, optical basicity, optical electronegativity, Urbach Energy, and the indirect bandgap, while RE3+ emission properties are only slightly modified. Under UV excitation, narrow emission bands are observed arising from 5D0→7FJ (J = 0, 1, 2, 3, and 4) transitions of Eu3+. At least two distinct Eu3+ lifetime values are observed, suggesting a spread of different ionic environments within the glass structure. Co-doping with Er3+/Yb3+ promotes emission in the infrared region, with a emission band maximum near 1535 nm and a width of 30.65 nm under excitation at 980 nm. Based on the results, these glasses may be potential candidates for energy conversion from infrared or UV region to the visible region and also infrared solid-state emitters.

Gamma-Ray Sensing Properties of Nd Doped Phosphate Glasses

Five selected Nd2O3 doped phosphate glass compositions are synthesized using melt quench technique. The physical properties such as density (ρ) and molar volume (Vm) are experimentally measured. The density increases whereas molar volume decreases with addition of Nd2O3 content. The radiation sensing properties for these rare earth (RE) element doped phosphate glass samples have been investigated. The photon attenuation and sensing parameters such as mass attenuation coefficient (μm), linear attenuation coefficient (μL), optimum thickness range (x opt), effective atomic number (Zeff), and mean free path (mfp) values are computed over wide gamma-ray energy range 1keV -100 GeV within framework of WinXCom software tool. The photon sensing properties of these rare earth doped phosphate glasses vary significantly on account of neodymium oxide content and photon energy. The mean free path (mfp) values of glass samples are found to decrease while the mass attenuation coefficient values rise as Nd2O3 concentration does.

Investigation of structural and optical properties: Tm2O3/Dy2O3 codoping in P2O5-MgO-NaF-CaF2 glass

Rare earth-doped glass is regarded as an excellent luminescent material and has been widely used in solid-state lighting. Here, the Tm3+/Dy3+ co-doped phosphate glasses revealed an increasing trend in density as the raising of Tm3+ contents, and the Urbach energies were 0.242∼0.374 eV based on transmission spectra. Under the 362 nm excitation, the white light with the chromaticity coordinates that were close to the value of standard white light was produced. The electric dipole-dipole interaction plays a major role in the energy transfer process from Tm3+ to Dy3+, and the glass exhibited a very high energy transfer efficiency of 64.44% according to the fluorescence spectra. Furthermore, the luminescent intensity of Tm3+/Dy3+ co-doped glasses at 150°C can still keep approximately 85.4% of its initial intensity and the glasses displayed excellent moisture-resistance (99.2%). Overall, the prepared Tm3+/Dy3+ co-doped glass exhibited potential applications in the field of W-LED and display devices.

Effect of silver nanoparticles on the visible upconversion emission of Er3+/Yb3+ co-doped SbPO4-GeO2 glasses

Rare earth-doped glasses are largely studied for developing new and efficient photonic devices. The influence of localized electric fields from the LSPR of metallic nanoparticles (MNP) on the rare-earth luminescent properties is a matter of study. This work describes the effect of Ag-MNP on the visible-upconversion emission of Er3+/Yb3+-co-doped SbPO4-GeO2 glass. Ag-MNP was obtained with an average size of ∼5 nm and a LSPR absorption band at 520 nm. A significant enhancement of the red emission (∼650 nm) of Er3+ as a function of Ag-MNPs content was observed. It showed silver nanocluster emission through excitation at infrared via energy transfer from Er3+ to the Ag nanoclusters. Photoluminescence spectroscopy revealed that longer heat treatment times increase the red emission and enhance the rapid depopulation of 4F9/2 level, reducing the lifetime by 57% due to the LSPR of Ag-MNPs in the vicinity of the Er3+ and Yb3+.

Optimization and analysis of process parameters of melt quenching technique for multiple performances of rare earth doped barium borate glass synthesis using Taguchi's design and grey relational approach

Glass materials with strong physical, structural, and optical properties are in high demand in today's social and industrial sectors. Researchers have recently established the extensive uses of these widely utilized glassy materials in optoelectronic devices, aerospace, nuclear industries, etc. Optimization usually plays a significant role in the synthesis of material. Hence, this article uses the statistical optimization of multiple process parameters of the melt quenching technique for rare earth doped barium borate glass 60B2O3-(40-X)BaO-XMO (MO-Er2O3/CeO2 and X = 0.5,1.0,1.5 mol percentage)by Taguchi's Design of Experiment. The multiple performance characteristics were studied using Grey relational analysis. An experimental format for preparing the Barium Borate glass was utilized with a standard L9 orthogonal array designed by Taguchi. Grey relational analysis was used to analyze the effects of processing parameters, including melting temperature, the composition of rare-earth oxide, and melting time of glasses on density, refractive index, and indirect bandgap. Analysis of variance (ANOVA) showed the influence of process parameters on the multiple response parameters as directed by the S/N ratio of the response parameter. The prediction of optimal conditions for contributing process parameters to the multiple response parameters was estimated efficiently. Additionally, as compared to the initial conditions, the optimal confirmatory experiment exhibited a considerable improvement in the response parameters (refractive index, density, and indirect bandgap). Grey relational grade and analysis of variance (ANOVA) revealed that melting temperature to be sole factor significantly affecting multiple responses with a 95% confidence level. The objective of the work is to optimize the melt quenching process parameters and their influence on the physical and optical properties of glass for photonic applications. Using this optimization method, melt quenching was found to be the most influential parameter contributing about 73–74% in tuning the desired response parameters. The findings also revealed a very less deviation between the statistically predicted and experimental data of response parameter, with deviation ranging from 0.37 to 2.14%. This good agreement between experimental and predicted values of response parameters indicated the suitability of Taguchi method of optimization for melt quenching technique.

Annealing duration dependent optical, nonlinear optical, and optical limiting properties of rare-earth doped glasses embedded with gold nanoparticles

In this work, the Eu2O3 doped B2O3 glass specimen embedded with gold nanoparticles (NPs) was designed by the process of melt-quenching and subjected for thermal treatment to understanding the efficacy of thermal dependency on the optical and nonlinear optical (NLO) characteristics. Linear optical studies have revealed a decrease trend in the energy band gap as the function of annealing duration, indicating the increase of non-bridging oxygen concentration in the glass host. The NLO properties were assessed in near-infrared region utilizing 150 fs laser pulses delivered at the rate of 80 MHz. The aperture free Z-scan measurements exhibited an increased nonlinear absorption coefficient with annealing duration. Further, the closed aperture Z-scan data depicted an increase trend in the positive nonlinear refraction with annealing duration and eventually reduced at the greater duration of annealing. The optical limiting studies demonstrated similar behaviour to the nonlinear absorption characteristics of studied glass samples. These results are related to the local field stimulated by surface plasmons of gold NPs near the Eu3+ ions during the exposure of glass to high fluence laser beam. Our results indicate that B2O3 glasses embedded with Au NPs heat-treated for 30 h at 450 °C are good candidates for nonlinear photonic, optoelectronic, and optical power limiting applications in photonics.

Impact of rare earth doping on the luminescence of lanthanum aluminum silicate glasses for radiation sensing

Large core soft glass fibers have been demonstrated to be promising candidates as intrinsic fiber sensors for radiation detection and dosimetry applications. Doping with rare earth ions enhanced their radiation sensitivity. SiO2-Al2O3-La2O3 (SAL) glasses offer easy fabrication of large core fibers with high rare earth concentration and higher mechanical strength than soft glasses. This paper evaluates the suitability of the SAL glass type for radiation dosimetry based on optically stimulated luminescence (OSL) via a comprehensive investigation of the spectroscopic and dosimetric properties of undoped and differently rare earth doped bulk SAL glass samples. Due to the low intensity of the rare earth luminescence peaks in the 250–400 nm OSL detection range, the OSL response for all the SAL glasses is not caused by the rare earth ions but by radiation-induced defects that act as intrinsic centers for the recombination of electrons and holes produced by the ionizing radiation, trapped in fabrication induced defect centers, and then released via stimulation with 470 nm light. The rare earth ions interfere with these processes involving intrinsic centers. This dosimetric behavior of highly rare earth doped SAL glasses suggests that enhancement of OSL response requires lower rare earth concentrations and/or longer wavelength OSL detection range.

Synthesis and characterization of rare-earth doped aluminium phosphate glasses

Sodium aluminium phosphate (NAP) glass is a potential candidate for the immobilization of minor actinides (MA). The composition of the NAP glass 38Na2O–30Al2O3–32P2O5 (mol %) was found to be the optimal choice, through experimental trials and specimens of this glass containing 1, 5, 10 and 15 wt% of the rare-earths (Ce, Pr, Nd and Gd-as surrogates for MA) were prepared by the melt quench technique. All these samples were X-ray amorphous, and were found to contain (PO4)−2 Q1 and (PO4)−1 Q2 units. Both Al2O3 and rare-earths were found to modify the structure of the phosphate glass significantly. Al2O3 plausibly acts as a network former at higher concentrations. The melting point, glass transition temperature, viscosity, Angell thermal stability and glass forming ability of these glasses increase with the concentration of the dopants, while their fragility decreased. Absolute values of the heat capacity of these glasses (Cp) as well as the attendant change in the heat capacity during the glass transition ΔCp showed an increase up to 5 wt % doping and a decrease subsequently when the concentration of the dopants were increased up to 15 wt%. Glasses containing 10 and 15 wt% dopants show sharper crystallization peaks while the crystallization is less pronounced in the rest of the glass samples. The rare-earth cations improve the strength of the glass when doped up to 5 wt%, beyond which the rigidity of the structure begins to fall. The networking due to complexation diminishes and leads to weaker chains resulting in the glasses with higher concentration of the rare-earths modifiers. These first results on the dependence of the structure and thermal properties of the NAP glass 38Na2O–30Al2O3–32P2O5 (mol%) doped with rare-earth reported here show that this glass could serve as a suitable matrix for immobilizing rare earths and minor actinides.

Influence of rare-earth ions on the radiation protection ability of some optical glasses containing Bi2O3 and SiO2

ObjectiveThis study probed the gamma ray shielding functionality of some rare earth doped bismuth-silicate glasses (BS). The mass attenuation coefficient MAC of pure BS (BS-Pure) and those with 2.5 mol% of Bi2O3 substituted with CeO2 (BS-Ce), Nd2O3 (BS-Nd), Sm2O3 (BS-Sm), and Eu2O3 (BS-Eu) was estimated. MethodThe experimental values of glass density and molar volume were systematically used to evaluate the radiation shielding properties of the studied optical glasses. The MAC was computed for photon energies between 0.015 and 15 MeV by employing Monte Carlo simulation and Phy-X software. MAC values were then used to extract all the other related parameters. ResultsMAC computed via the two approached agrees well within 1.9%. MAC of the glasses fluctuates between 0.041 and 100.044 cm2g−1 for BS-Pure; 0.041 – 98.725 cm2g−1 for BS-Ce; 0.041 – 99.249 cm2g−1 for BS-Nd; 0.04 – 99.335 cm2g−1 for BS-Sm; and 0.041 – 99.061 cm2g−1 for BS-Eu. Also, the effective atomic number of the glasses were within the range of 38.707–81.874 for BS-Pure, 38.397–81.509 for BS-Ce, 38.377–81.366 for BS-Nd, 38.402–81.366 for BS-Sm and 38.414–81.368 for BS-Eu. ConclusionCompared to traditional photon shields such as concrete, RS-360 commercial glasses, recently investigated heavy glasses, polymer and rocks, the BS-X glasses displayed superior shielding potential. The BS-X glasses thus could function well in gamma radiation shielding technology.

Research on rare earth doped mesoporous bioactive glass nanospheres. Ⅰ. Similarity of in vitro biological effects

Rare earth (RE) elements, known as “industrial vitamins,” are widely used in advanced materials to optimize their properties. In this work, RE (La, Ce, Pr, Nd, Eu and Dy)-doped mesoporous bioactive glass nanospheres (RE/MBG) were synthesized using the sol-gel method. It was proven for the first time that the homology of RE ions confers functional similarity in bone tissue engineering, and the desired properties are obtained by guiding cell behavior and changing the physicochemical properties of biomaterials. It was found that RE/MBG nanospheres have similar structures and therefore similar properties, such as sustained drug release and anticancer prope dy provides a feasible strategy for the development, evaluation and basic research of homologous group ion-doped nanobiomaterials in bone tissue engineering.

Effect of chirp on supercontinuum generation from Barium Zinc Borate glasses

Supercontinuum generation from undoped and rare-earth doped Barium Zinc Borate glass with variation in input chirp of a fs pulse is investigated. With varying chirp, the most intense peak of the supercontinuum (SC) spectrum is observed. The peak shift for rare-earth-doped samples with the negatively chirped pulses was not significant compared to that observed with positively chirped pulses. Comparing the evolution of SCG with varying input pulse chirp suggested a material dependency of supercontinuum generation under chirping.

Optical Properties of Transparent Rare-Earth Doped Sol-Gel Derived Nano-Glass Ceramics.

Rare-earth doped oxyfluoride glass ceramics represent a new generation of tailorable optical materials with high potential for optical-related applications such as optical amplifiers, optical waveguides, and white LEDs. Their key features are related to the high transparency and remarkable luminescence properties, while keeping the thermal and chemical advantages of oxide glasses. Sol-gel chemistry offers a flexible synthesis approach with several advantages, such as lower processing temperature, the ability to control the purity and homogeneity of the final materials on a molecular level, and the large compositional flexibility. The review will be focused on optical properties of sol-gel derived nano-glass ceramics related to the RE-doped luminescent nanocrystals (fluorides, chlorides, oxychlorides, etc.) such as photoluminescence, up-conversion luminescence, thermoluminescence and how these properties are influenced by their specific processing, mostly focusing on the findings from our group and similar ones in the literature, along with a discussion of perspectives, potential challenges, and future development directions.

Influenceof Sm2O3 and CaF2 Concentrationonthe Enhancement of Luminescence and Red Colour in Borosilicate Glass

A series of Samarium (Sm) doped borosilicate glass was designed and prepared by melt-quenching method to realize the controllable and adjustable red emission for further applications of rare-earth doped glass. The influence of Sm 2O3 and CaF2 concentration on the structure, composition and luminescence property of samples were investigated and revealed. It was shown that the samples had glassy non-crystalline nature and high transparency within the visible light region. The characteristic transitions of Sm3+ ion assigned to 4G5/2 → 6H J /2 (J = 5, 7, 9, 11) were detected, which realized the red-orange emission in the host. Concentration quenching occurred when Sm2O3 and CaF 2 contents were 1.0 and 8 mol%, respectively. Dipole-dipole interactions were the effective mechanisms of energy transfer and quenching between Sm 3+ ions. M eanwhile, with fixed Sm 2O3 concentration, both the PL intensity and the fluorescence lifetime increased as the CaF2 content enhanced. In a word, the orange/red ( O/R) ratio, Commission Internationale de ĺEclairage (CIE) chromatic coordinates and luminescence colour of the samples are dependent and adjustable by the concentration of Sm2O3 and CaF2, which helps to fabricate tunable efficiency light-emitting materials and extend their applications by regulating the composition of glass.

Effect of rare earth dopants on the radiation shielding properties of barium tellurite glasses

Rare earth doped barium tellurite glasses were synthesised and explored for their radiation shielding applications. All the samples showed good thermal stability with values varying between 101 °C and 135 °C based on dopants. Structural properties showed the dominance of matrix elements compared to rare earth dopants in forming the bridging and non-bridging atoms in the network. Bandgap values varied between 3.30 and 4.05 eV which was found to be monotonic with respective rare earth dopants indicating their modification effect in the network. Various radiation shielding parameters like linear attenuation coefficient, mean free path and half value layer were calculated and each showed the effect of doping. For all samples, LAC values decreased with increase in energy and is attributed to photoelectric mechanism. Thulium doped glasses showed the highest value of 1.18 cm−1 at 0.245 MeV for 2 mol.% doping, which decreased in the order of erbium, holmium and the base barium tellurite glass, while half value layer and mean free paths showed an opposite trend with least value for 2 mol.% thulium indicating that thulium doped samples are better attenuators compared to undoped and other rare earth doped samples. Studies indicate an increased level of thulium doping in barium tellurite glasses can lead to efficient shielding materials for high energy radiation.