Colour tuning and energy transfer pathways in MgAl 2 O 4 triply doped with 0.1% Ce 3+ , 0.1% Eu 2+ , x% Tb 3+(0⩽x⩽2%)nanocrystals synthesized using sol-gel process

ABSTRACTThe sol-gel process provides new opportunities for the synthesis of photonic materials. Sol-gel chemistry is mainly based on inorganic polymerization reactions performed in solution at lower temperatures than conventional chemical methods. Homogeneous doping by mixing components at a molecular level and synthesis of mixed organic-inorganic materials can then be performed. Luminescent properties of dyes inside silica, aluminosilicates or transition metal oxide based gels have been studied extensively. Much less work has been devoted to the study of energy transfer (ET) inside sol-gel matrices. Sol-gel materials provide the opportunity to investigate dye-dye ET, as well as dye-ion ET. This communication presents an optical study of a variety of sol-gel matrices (SiO2, Al2O3, ZrO2 based gels) codoped with rhodamine 6G(Rh6G) and europium. Different types of ET are observed among Rh6G, Eu3+ and Eu2+. The Eu2+/Eu3+ ratio is found to be strongly dependent on the host matrices. The reduction of Eu3+ t· Eu2+ in dried gels may relate to the presence of Rh6G.

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The crystallization of thin-film ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122095 ◽

1992 ◽

Vol 50 (1) ◽

pp. 338-339

Author(s):

J.M. Schwartz ◽

L.F. Francis ◽

L.D. Schmidt ◽

P.S. Schabes-Retchkiman

Keyword(s):

Thin Films ◽

Grain Size ◽

Sol Gel ◽

Processing Route ◽

Small Areas ◽

Ceramic Thin Films ◽

Complex Shapes ◽

Sol Gel Process ◽

Ceramic Precursors ◽

Crystalline Ceramic

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.

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Epitaxial Growth of Sr0.3Ba0.7Nb2O6 Thin Films Prepared by Sol-Gel Process

MRS Proceedings ◽

10.1557/proc-606-181 ◽

1999 ◽

Vol 606 ◽

Cited By ~ 2

Author(s):

Keishi Nishio ◽

Jirawat Thongrueng ◽

Yuichi Watanabe ◽

Toshio Tsuchiya

Keyword(s):

Thin Film ◽

Thin Films ◽

Epitaxial Growth ◽

Raw Materials ◽

Substrate Surface ◽

Sol Gel ◽

Tungsten Bronze ◽

Monomethyl Ether ◽

Tetragonal Tungsten Bronze ◽

Sol Gel Process

AbstructWe succeeded in the preparation of strontium-barium niobate (Sr0.3Ba0.7Nb2O6 : SBN30)that have a tetragonal tungsten bronze type structure thin films on SrTiO3 (100), STO, or La doped SrTiO3 (100), LSTO, single crystal substrates by a spin coating process. LSTO substrate can be used for electrode. A homogeneous coating solution was prepared with Sr and Ba acetates and Nb(OEt)5 as raw materials, and acetic acid and diethylene glycol monomethyl ether as solvents. The coating thin films were sintered at temperature from 700 to 1000°C for 10 min in air. It was confirmed that the thin films on STO substrate sintered above 700°C were in the epitaxial growth because the 16 diffraction spots were observed on the pole figure using (121) reflection. The <130> and <310> direction of the thin film on STO were oriented with the c-axis in parallel to the substrate surface. However, the diffraction spots of thin film on LSTO substrate sintered at 700°C were corresponds to the expected pattern for (110).

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UV Curable Organic-Inorganic Hybrid Materials

MRS Proceedings ◽

10.1557/proc-628-cc6.14 ◽

2000 ◽

Vol 628 ◽

Cited By ~ 1

Author(s):

Guang-Way Jang ◽

Ren-Jye Wu ◽

Yuung-Ching Sheen ◽

Ya-Hui Lin ◽

Chi-Jung Chang

Keyword(s):

Hybrid Materials ◽

Colloidal Silica ◽

Sol Gel ◽

Solution Ph ◽

Uv Curable ◽

Inorganic Hybrid ◽

Degradation Temperature ◽

Sol Gel Process ◽

The Stability ◽

Thermal Degradation Temperature

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥

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Halogenation of ORMOSIL: A Promising Rout for Tailoring Optical Absorptions

MRS Proceedings ◽

10.1557/proc-771-l4.1 ◽

2003 ◽

Vol 771 ◽

Author(s):

Amir Fardad ◽

Wei Liang ◽

Yadong Zhang ◽

Bryson Case ◽

Shibin Jiang ◽

...

Keyword(s):

Process Parameters ◽

Sol Gel ◽

Fiber Amplifiers ◽

Grignard Reaction ◽

Coupling Loss ◽

Beam Splitters ◽

Silicon Technology ◽

Sol Gel Process ◽

Propagation Losses ◽

Signal Intensities

AbstractFluorinated and photo-imageable precursors are synthesized through a Barbier-Grignard reaction for 1550-nm window. The precursors are used for the sol-gel process of integrated optic components for silica-on-silicon technology. Material compositions and process parameters are optimized to achieve internal absorptions >0.1 dB/cm and propagation losses of about 0.5 dB/cm at 1550 nm. Compact 1×16 Beam splitters are designed and fabricated which exhibit >0.3 dB power uniformity, >0.1 dB PDL and 1.5 dB coupling loss. By hybrid integration of the passive splitters and in-house fiber amplifiers, amplifying splitters are demonstrated at various signal intensities.

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