Facile synthesis of monodisperse SrAl2O4:Eu2+ cage-like microspheres with an excellent luminescence quantum yield

2018 ◽  
Vol 6 (13) ◽  
pp. 3346-3351 ◽  
Author(s):  
Jun Wan ◽  
Yuting Zhang ◽  
Yuan Wang ◽  
Ronghua Ma ◽  
Yimin Wu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Quantum Yield ◽  
Sol Gel ◽  
Subsequent Heat Treatment ◽  
Luminescence Quantum Yield ◽  
Facile Synthesis

SrAl2O4:Eu2+ cage-like microspheres are prepared by a sol–gel route and subsequent heat treatment. The optimum quantum yield of the cage-like microspheres is 94.94%.

Facile synthesis of monodisperse YAG:Ce3+ microspheres with high quantum yield via an epoxide-driven sol–gel route

2017 ◽  
Vol 5 (35) ◽  
pp. 8952-8957 ◽  
Author(s):  
Yuting Zhang ◽  
Xvsheng Qiao ◽  
Jun Wan ◽  
Li-ang Wu ◽  
Bing Chen ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Quantum Yield ◽  
Sol Gel ◽  
Subsequent Heat Treatment ◽  
Luminescence Quantum Yield ◽  
High Quantum Yield ◽  
Facile Synthesis ◽  
High Quantum ◽  
Reducing Atmosphere

Monodisperse YAG:Ce3+ microspheres have been synthesized through a fast epoxide-driven sol–gel route and subsequent heat treatment under a reducing atmosphere. The luminescence quantum yield of the 6 mol% Ce3+ ion doped YAG microspheres was more than 90%.

Synthesis and luminescence properties of colloidal lanthanide doped YVO4

2001 ◽  
Vol 667 ◽  
Author(s):  
Arnaud Huignard ◽  
Thierry Gacoin ◽  
Frédéric Chaput ◽  
Jean-Pierre Boilot ◽  
Patrick Aschehoug ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Room Temperature ◽  
Sol Gel ◽  
Precursor Solution ◽  
Silica Matrix ◽  
Luminescence Quantum Yield ◽  
Colloidal Solutions ◽  
Silicon Alkoxide ◽  
Crystalline Defects ◽  
Hydroxylated Surface

ABSTRACTAqueous colloidal solutions of well dispersed YVO4:Ln (Ln = Eu, Nd) nanoparticles are synthesized through precipitation reactions at room temperature. In the case of YVO4:Eu, a luminescence quantum yield of 15% is found, which is not as high as in the bulk due to the existence of residual crystalline defects and nonradiative relaxations from the hydroxylated surface. Appropriate hydrothermal annealing and deuteration of the surface allow to rise the yield up to 38%. Incorporation of the nanocrystals into a transparent silica matrix is achieved through preliminary coating of the particles with a functionnalized silicon alkoxide and further dispersion into a sol-gel precursor solution. Such sol-gel materials doped with YVO4:Nd nanocrystals are transparent and exhibit the typical emission at 1.06 μm of the Nd3+ ion.

Facile synthesis of monolithic mayenite with well-defined macropores via an epoxide-mediated sol–gel process accompanied by phase separation

2014 ◽  
Vol 38 (12) ◽  
pp. 5832-5839 ◽  
Author(s):  
Xingzhong Guo ◽  
Xiaobo Cai ◽  
Jie Song ◽  
Yang Zhu ◽  
Kazuki Nakanishi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Phase Separation ◽  
Sol Gel ◽  
High Porosity ◽  
Macroporous Structure ◽  
Facile Synthesis ◽  
Sol Gel Process

Monolithic mayenite has been successfully prepared via a sol–gel process followed by heat-treatment, exhibiting co-continuous macroporous structure and high porosity.

A novel approach to synthesis of nanosize MgAl2O4 spinel powder through sol–gel citrate technique and subsequent heat treatment

2009 ◽  
Vol 35 (3) ◽  
pp. 933-937 ◽  
Author(s):  
Ali Saberi ◽  
Farhad Golestani-Fard ◽  
Monika Willert-Porada ◽  
Zahra Negahdari ◽  
Christian Liebscher ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Sol Gel ◽  
Subsequent Heat Treatment ◽  
Mgal2o4 Spinel ◽  
Novel Approach ◽  
Spinel Powder

Higher Intrinsic Quantum Yield of Eu3+-Doped Zn2sio4 Obtained by Sol-Gel Process, Calculated by Judd - Ofelt Theory

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Jefferson Luis Ferrari ◽  
Adriana Souza de Oliveira ◽  
Juliana Maria Martins Buarque ◽  
Luiz Fernando Cappa de Oliveira ◽  
Clebio Soares Nascimento Jr. ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Quantum Yield ◽  
Annealing Temperature ◽  
Sol Gel ◽  
High Symmetry ◽  
Ofelt Theory ◽  
Higher Symmetry ◽  
Molar Ratios ◽  
Sol Gel Process ◽  
Photoluminescent Materials

The sol-gel process allows the obtaining of Eu3+-doped Zn2SiO4with 1 mol% with different molar ratios between Zn2+ and Si4+. The materials reported here were obtained with a resistive furnace at 600, 900, 1000 and 1100°C degree, during 2 h. All the materials exhibited an intense photoluminescence emission with bands assigned to the Eu3+ transitions. Among the materials studied, the samples containing 70 and 80% of Si4+, exhibited higher Eu3+ lifetimes values. The predominance of the quartz phase decreases micro deformations and the location of the Eu3+ ions in higher symmetry sites, reducing the intensity of the photoluminescent materials. The increasing of annealing temperature contributes to the detrimental lifetime and luminescence materials due to the location of the Eu3+ in the site of high symmetry. Through Judd-Ofelt theory was possible to obtain higher values of intrinsic quantum yield (QLn Ln) between 32 and 66% dependent on the temperature of heat-treatment, in comparison with the same material reported in the literature. Keywords: Orthosilicates; Photoluminescence; Rare Earth; Europium;

Adhesion Strength of Sol-Gel Derived FHA Coating on Laser Gas Nitrided Pure Ti

2009 ◽  
Vol 610-613 ◽  
pp. 1294-1297 ◽  
Author(s):  
San Jun Wang ◽  
Sen Yang ◽  
Ming Run Wang
Keyword(s):  
Heat Treatment ◽  
Adhesion Strength ◽  
Titanium Surface ◽  
Sol Gel ◽  
Dendritic Structure ◽  
Subsequent Heat Treatment ◽  
Gas Nitriding ◽  
Gel Technique ◽  
Nitrided Titanium ◽  
Titanium Substrates

Fluor-hydroxyapatite (FHA) films were deposited on titanium and laser gas nitrided titanium substrates using sol-gel technique respectively. Typical apatite structures were obtained for all coatings after dipping and subsequent heat treatment from 600°C to 800°C. The obtained films were uniform and dense, with a thickness of 5 μm. The 3-D TiN dendritic structure fabricated on the surface of Ti plate using laser gas nitriding technique in advance should be help anchor the HA/FHA coating and improved the interfacial adherence significantly compared with the naked titanium surface.

Effect of MCl (M = Na, K) addition on microstructure and electrical conductivity of forsterite

2020 ◽  
Vol 92 (1) ◽  
pp. 10901
Author(s):  
Saloua El Asri ◽  
Hamid Ahamdane ◽  
Lahoucine Hajji ◽  
Mohamed El Hadri ◽  
Moulay Ahmed El Idrissi Raghni ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Single Phase ◽  
Sol Gel ◽  
Complex Impedance ◽  
Transmission Spectra ◽  
Electrical Measurements ◽  
Cation Type ◽  
Edx Analyses ◽  
The Fourier Transform

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.

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