Structural and Spectroscopic Assessment of Er3+-Activated SiO2-HfO2 Glass Ceramics Planar Waveguides

2008 ◽  
Vol 55 ◽  
pp. 56-61
Author(s):  
L. Minati ◽  
Giorgio Speranza ◽  
Yoann Jestin ◽  
Cristina Armellini ◽  
Andrea Chiappini ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Spinodal Decomposition ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Emission Spectra ◽  
Planar Waveguides ◽  
Material Structure ◽  
Crystalline Environment ◽  
Concentration Threshold

Two series of xHfO2 - (100-x) SiO2 (x=10, 20, 30 mol%) glass-ceramics planar waveguides doped with 0.3 mol% Er3+ ions were prepared by the sol-gel route. A thermal treatment at 1000°C was applied to the second series of samples to nucleate HfO2 crystals. The waveguides were analyzed by X-ray photoelectron spectroscopy to study the effect of the Hf concentration and of the annealing on the material structure. XPS shows that in the first series of samples a Hf concentration threshold exists. Above this threshold the material undergoes a spinodal decomposition with formation of HfO2 rich domains. In the second series of samples the presence of thermal treatment lowers the concentration threshold so that the phase separation occurs also at a Hf concentration of 10%mol. In the waveguides where spinodal decomposition in present, the emission spectra from the Er3+ ions reveal a sensible narrowing of the 4I13/2 → 4I15/2 line. This demonstrates the presence of a crystalline environment for the Er3+ ions since the inhomogeneous broadening due to the disordered glassy network is suppressed. These results may have important implications for the fabrication of photonic devices with increased efficiency.

scholarly journals Luminescence of SiO2-BaF2:Tb3+, Eu3+ Nano-Glass-Ceramics Made from Sol–Gel Method at Low Temperature

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 259
Author(s):  
Natalia Pawlik ◽  
Barbara Szpikowska-Sroka ◽  
Tomasz Goryczka ◽  
Ewa Pietrasik ◽  
Wojciech A. Pisarski
Keyword(s):  
Sol Gel ◽  
Three Dimensional ◽  
Glass Ceramics ◽  
Emission Spectra ◽  
Scanning Calorimetry ◽  
Light Emitting ◽  
Co Doping ◽  
Dsc Measurements ◽  
Decay Times

The synthesis and characterization of multicolor light-emitting nanomaterials based on rare earths (RE3+) are of great importance due to their possible use in optoelectronic devices, such as LEDs or displays. In the present work, oxyfluoride glass-ceramics containing BaF2 nanocrystals co-doped with Tb3+, Eu3+ ions were fabricated from amorphous xerogels at 350 °C. The analysis of the thermal behavior of fabricated xerogels was performed using TG/DSC measurements (thermogravimetry (TG), differential scanning calorimetry (DSC)). The crystallization of BaF2 phase at the nanoscale was confirmed by X-ray diffraction (XRD) measurements and transmission electron microscopy (TEM), and the changes in silicate sol–gel host were determined by attenuated total reflectance infrared (ATR-IR) spectroscopy. The luminescent characterization of prepared sol–gel materials was carried out by excitation and emission spectra along with decay analysis from the 5D4 level of Tb3+. As a result, the visible light according to the electronic transitions of Tb3+ (5D4 → 7FJ (J = 6–3)) and Eu3+ (5D0 → 7FJ (J = 0–4)) was recorded. It was also observed that co-doping with Eu3+ caused the shortening in decay times of the 5D4 state from 1.11 ms to 0.88 ms (for xerogels) and from 6.56 ms to 4.06 ms (for glass-ceramics). Thus, based on lifetime values, the Tb3+/Eu3+ energy transfer (ET) efficiencies were estimated to be almost 21% for xerogels and 38% for nano-glass-ceramics. Therefore, such materials could be successfully predisposed for laser technologies, spectral converters, and three-dimensional displays.

scholarly journals SiO2-SnO2:Er3+ Glass-Ceramic Monoliths

2018 ◽  
Author(s):  
Lam Thi Ngoc Tran ◽  
Damiano Massella ◽  
Lidia Zur ◽  
Alessandro Chiasera ◽  
Stefano Varas ◽  
...  
Keyword(s):  
Rare Earth ◽  
Optical Sensors ◽  
Tin Dioxide ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Building Blocks ◽  
Spectroscopic Properties ◽  
Silica Matrix ◽  
Rare Earth Ions ◽  
Planar Waveguides

The development of efficient luminescent systems, such as microcavities, solid state lasers, integrated optical amplifiers, optical sensors is the main topic in glass photonics. The building blocks of these systems are glass-ceramics activated by rare earth ions because they exhibit specific morphologic, structural and spectroscopic properties. Among various materials that could be used as nanocrystals to be imbedded in silica matrix, tin dioxide presents some interesting peculiarities, e.g. the presence of tin dioxide nanocrystals allows increase in both solubility and emission of rare earth ions. Here, we focus our attention on Er3+ - doped silica – tin dioxide photonic glass-ceramics fabricated by sol-gel route. Although the SiO2-SnO2:Er3+ could be fabricated in different geometrical systems: thin films, monoliths and planar waveguides we herein limit ourselves to the monoliths. The effective role of tin dioxide as luminescence sensitizer for Er3+ ions is confirmed by spectroscopic measurements and detailed fabrication protocols are discussed.

Intense UV and visible up-conversion emissions from RE-doped SiO2–BaGdF5 nano-glass-ceramics

2018 ◽  
Vol 20 (32) ◽  
pp. 20910-20918 ◽  
Author(s):  
J. del-Castillo ◽  
A. C. Yanes
Keyword(s):  
Thermal Treatment ◽  
Sol Gel ◽  
Glass Ceramics ◽  
High Efficient ◽  
Gel Glasses

High-efficient UV and VIS up-conversion RE-doped nano-glass-ceramics comprising BaGdF5 nanocrystals, have been developed under thermal treatment of precursor sol–gel glasses.

scholarly journals Europium-Doped Sol-Gel SiO2-Based Glasses: Effect of the Europium Source and Content, Magnesium Addition and Thermal Treatment on Their Photoluminescence Properties

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1768 ◽  
Author(s):  
Hussein Fneich ◽  
Nathalie Gaumer ◽  
Stéphane Chaussedent ◽  
Wilfried Blanc ◽  
Ahmad Mehdi
Keyword(s):  
Thermal Treatment ◽  
Glass Structure ◽  
Sol Gel ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Aqueous Environment ◽  
Silica Glasses ◽  
Sol Gel Process ◽  
Before And After ◽  
Mg Addition

Rare-earth doped silica-based glasses lead the optical materials due to their tailorable spectroscopic and optical properties. In this context, we took advantage of the sol-gel process to prepare various Eu-doped silica glasses to study their luminescent properties before and after annealing at 900 °C. The effect of magnesium on these properties was studied in comparison with Mg-free-glass. Using TEM, nitrogen sorption, XRD and FT-IR, we confirmed that the magnesium modifies the glass structure and the thermal treatment eliminates the aqueous environment, modifying the structure ordering. The emission spectra and the decay time curves show the advantages of the Mg addition and the annealing on the photoluminescent properties.

scholarly journals Structural and Photoluminescence Investigations of Tb3+/Eu3+ Co-Doped Silicate Sol-Gel Glass-Ceramics Containing CaF2 Nanocrystals

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 754
Author(s):  
Natalia Pawlik ◽  
Barbara Szpikowska-Sroka ◽  
Tomasz Goryczka ◽  
Joanna Pisarska ◽  
Wojciech A. Pisarski
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Emission Spectra ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Co Doping ◽  
Near Ultraviolet ◽  
Transmission Electron ◽  
Co Doped

In this work, the series of Tb3+/Eu3+ co-doped xerogels and derivative glass-ceramics containing CaF2 nanocrystals were prepared and characterized. The in situ formation of fluoride crystals was verified by an X-ray diffraction technique (XRD) and transmission electron microscopy (TEM). The studies of the Tb3+/Eu3+ energy transfer (ET) process were performed based on excitation and emission spectra along with luminescence decay analysis. According to emission spectra recorded under near-ultraviolet (NUV) excitation (351 nm, 7F6 → 5L9 transition of Tb3+), the mutual coexistence of the 5D4 → 7FJ (J = 6–3) (Tb3+) and the 5D0 → 7FJ (J = 0–4) (Eu3+) luminescence bands was clearly observed. The co-doping also resulted in gradual shortening of a lifetime from the 5D4 state of Tb3+ ions, and the ET efficiencies were varied from ηET = 11.9% (Tb3+:Eu3+ = 1:0.5) to ηET = 22.9% (Tb3+:Eu3+ = 1:2) for xerogels, and from ηET = 25.7% (Tb3+:Eu3+ = 1:0.5) up to ηET = 67.4% (Tb3+:Eu3+ = 1:2) for glass-ceramics. Performed decay analysis from the 5D0 (Eu3+) and the 5D4 (Tb3+) state revealed a correlation with the change in Tb3+–Eu3+ and Eu3+–Eu3+ interionic distances resulting from both the variable Tb3+:Eu3+ molar ratio and their partial segregation in CaF2 nanophase.

scholarly journals SiO2-SnO2:Er3+ Glass-Ceramic Monoliths

2018 ◽  
Vol 8 (8) ◽  
pp. 1335 ◽  
Author(s):  
Lam Tran ◽  
Damiano Massella ◽  
Lidia Zur ◽  
Alessandro Chiasera ◽  
Stefano Varas ◽  
...  
Keyword(s):  
Rare Earth ◽  
Optical Sensors ◽  
Tin Dioxide ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Building Blocks ◽  
Spectroscopic Properties ◽  
Silica Matrix ◽  
Rare Earth Ions ◽  
Planar Waveguides

The development of efficient luminescent systems, such as microcavities, solid-state lasers, integrated optical amplifiers, and optical sensors is the main topic in glass photonics. The building blocks of these systems are glass-ceramics activated by rare-earth ions because they exhibit specific morphologic, structural, and spectroscopic properties. Among various materials that could be used as nanocrystals to be imbedded in a silica matrix, tin dioxide presents some interesting peculiarities, e.g., the presence of tin dioxide nanocrystals allows an increase in both solubility and emission of rare-earth ions. Here, we focus our attention on Er3+—doped silica—tin dioxide photonic glass-ceramics fabricated by a sol-gel route. Although the SiO2-SnO2:Er3+ could be fabricated in different forms, such as thin films, monoliths, and planar waveguides, we herein limit ourselves to the monoliths. The effective role of tin dioxide as a luminescence sensitizer for Er3+ ions is confirmed by spectroscopic measurements and detailed fabrication protocols are discussed.

scholarly journals The Effect of Size and Thermal Treatment on the Photoluminescent Properties of Europium-Doped SiO2 Nanoparticles Prepared in One Pot by Sol-Gel

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1607
Author(s):  
Hussein Fneich ◽  
Nathalie Gaumer ◽  
Stéphane Chaussedent ◽  
Ahmad Mehdi ◽  
Wilfried Blanc
Keyword(s):  
Thermal Treatment ◽  
Sol Gel ◽  
Emission Spectra ◽  
Local Environment ◽  
Sio2 Nanoparticles ◽  
Aqueous Environment ◽  
X Ray Diffraction ◽  
One Pot ◽  
Transmission Electron ◽  
Structure Disorder

Europium (Eu)-doped silica nanoparticles have attracted great interest for different applications, in particular in biomedicine as biosensors or for tissue regeneration. Sol-gel is the most common process used to prepare those particles, with size varying from tens to hundreds of nanometers. In this article, we focus our attention on the comparison between two commonly used sol-gel derived methods: reverse microemulsion (for particles smaller than 100 nm) and Stöber method (for particles larger than 100 nm). Europium concentration was varied between 0.2 and 1 mol%, and the nanoparticle diameters were 10, 50 and 100 nm. The link between the local environment of europium ions and their optical properties was investigated and discussed. Using Transmission Electron Microscopy, nitrogen sorption, X-ray diffraction, Fourier-Transform Infra-Red and pulsed doubled Nd:YAG laser, we confirmed that fluorescence lifetime was improved by thermal treatment at 900 °C due to the elimination of aqueous environment and modification of structure disorder. The size of nanoparticles, the amount of europium and the thermal treatment of obtained materials influence the emission spectra and the decay curves of Eu3+.

Sol–gel derived Ce3+-doped aluminosilicate planar waveguides: a study by X-ray photoelectron spectroscopy

1999 ◽  
Vol 142 (1-4) ◽  
pp. 243-247 ◽  
Author(s):  
Jean-Marie Nédélec ◽  
Léon Gengembre ◽  
Sylvia Turrell ◽  
Mohamed Bouazaoui ◽  
Jean Grimblot
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Planar Waveguides ◽  
X Ray

scholarly journals Influence of thermal treatment on the structure and in vitro bioactivity of sol-gel prepared CaO-SiO2-P2O5 glass-ceramics

2014 ◽  
Vol 8 (3) ◽  
pp. 155-166 ◽  
Author(s):  
Lachezar Radev
Keyword(s):  
Thermal Treatment ◽  
Calcium Silicate ◽  
Sol Gel ◽  
Glass Ceramics ◽  
In Vitro Test ◽  
In Vitro Bioactivity ◽  
X Ray ◽  
Vitro Test ◽  
Sbf Solution

Nowadays there is a substantial practical interest in the in vitro bioactivity of calcium silicate phosphate (CSP) glass-ceramics and carbonate apatite (CO3HA) formation on their surfaces after in vitro test in simulated body fluid (SBF). The main purpose of the presented article is the evaluation of the chemical composition of the gel with nominal composition 70.59 CaO:28.23 SiO2:1.18 P2O5 (mol.%) on the structure, crystallization behaviour and in vitro bioactivity in SBF solution for 14 and 28 days. The prepared glass-ceramics have been synthesized via a polystep sol-gel method. The structure of the obtaining samples was studied by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). After thermal treatment of the samples XRD confirmed the presence of ?-Ca2SiO4 and Ca15(PO4)2(SiO4)6, and indicated that at 1500?C Ca15(PO4)2(SiO4)6 becomes predominant phase. FTIR revealed the presence of all characteristics bands for calcium silicate phosphate (CSP) bonds. SEM monitors the presence of particles with different morphology. After in vitro test in SBF, FTIR depicted that B-type carbonate containing hydroxyapatite (CO3HA) is preferentially formed on the immersed glass-ceramics. SEMof the precipitated layers showed the presence of HA spheres. The changes in SBF solution after soaking the samples were recorded by inductively coupled plasma atomic emission spectroscopy (ICP-AES).

scholarly journals Influence of Calcination Temperature on Crystal Growth and Optical Characteristics of Eu3+ Doped ZnO/Zn2SiO4 Composites Fabricated via Simple Thermal Treatment Method

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 115
Author(s):  
Suhail Huzaifa Jaafar ◽  
Mohd Hafiz Mohd Zaid ◽  
Khamirul Amin Matori ◽  
Sidek Hj. Ab Aziz ◽  
Halimah Mohamed Kamari ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Band Gap ◽  
Calcination Temperature ◽  
Emission Intensity ◽  
Emission Spectra ◽  
Treatment Method ◽  
Absorption Bands ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Zno Crystal

This research paper proposes the usage of a simple thermal treatment method to synthesis the pure and Eu3+ doped ZnO/Zn2SiO4 based composites which undergo calcination process at different temperatures. The effect of calcination temperatures on the structural, morphological, and optical properties of ZnO/Zn2SiO4 based composites have been studied. The XRD analysis shows the existence of two major phases which are ZnO and Zn2SiO4 crystals and supported by the finding in the FT-IR. The FESEM micrograph further confirms the existence of both ZnO and Zn2SiO4 crystal phases, with progress in the calcination temperature around 700–800 °C which affects the existence of the necking-like shape particle. Absorption humps discovered through UV-Vis spectroscopy revealed that at the higher calcination temperature effects for higher absorption intensity while absorption bands can be seen at below 400 nm with dropping of absorption bands at 370–375 nm. Two types of band gap can be seen from the energy band gap analysis which occurs from ZnO crystal and Zn2SiO4 crystal progress. It is also discovered that for Eu3+ doped ZnO/Zn2SiO4 composites, the Zn2SiO4 crystal (5.11–4.71 eV) has a higher band gap compared to the ZnO crystal (3.271–4.07 eV). While, for the photoluminescence study, excited at 400 nm, the emission spectra of Eu3+ doped ZnO/Zn2SiO4 revealed higher emission intensity compared to pure ZnO/Zn2SiO4 with higher calcination temperature exhibit higher emission intensity at 615 nm with 700 °C being the optimum temperature. The emission spectra also show that the calcination temperature contributed to enhancing the emission intensity.

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