scholarly journals Sol-Gel-Derived Silica Films With Tailored Microstructures for Applications Requiring Organic Dyes

1994 ◽  
Vol 346 ◽  
Author(s):  
Monica N. Logan ◽  
S. Prabakar ◽  
C. Jeffrey Brinker
Keyword(s):  
Thin Films ◽  
Volume Fraction ◽  
Organic Dyes ◽  
Film Formation ◽  
Sol Gel ◽  
Film Deposition ◽  
Small Pore ◽  
Sol Gel Process ◽  
Acid And Base ◽  
Kinetic Effects

ABSTRACTA three-step sol-gel process was developed to prepare organic dye-doped thin films with tailored porosity for applications in chemical sensing and optoelectronics. Varying the acid- and base-catalyzed hydrolysis steps of sols prepared from tetraethoxysilane with identical final H2O/Si ratios, dilution factors and pH resulted in considerably different distributions of the silicate polymers in the sol (determined by 29Si NMR) and considerably different structures for the polymer clusters (determined by SAXS). During film formation these kinetic effects cause differences in the packing and collapse of the silicate network, leading to thin films with different refractive indices and volume fraction porosities. Under conditions where small pore-plugging species were avoided, the porosities of as-deposited films could be varied by aging the sol prior to film deposition. This strategy, which relies on the growth and aggregation of fractal polymeric clusters, is compatible with the low temperature and near neutral pH requirements of organic dyes.

Sol-gel derived Ba(Mg1/3Ta2/3)O3 thin films: Preparation and structure

1997 ◽  
Vol 12 (3) ◽  
pp. 596-599 ◽  
Author(s):  
Ji Zhou ◽  
Qing-Xin Su ◽  
K. M. Moulding ◽  
D. J. Barber
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Small Grains

Ba(Mg1/3Ta2/3)O3 thin films were prepared by a sol-gel process involving the reaction of barium isopropoxide, tantalum ethoxide, and magnesium acetate in 2-methoxyethanol and subsequently hydrolysis, spin-coating, and heat treatment. Transmission electron microscopy, x-ray diffraction, and Raman spectroscopy were used for the characterization of the thin films. It was shown that the thin films tend to crystallize with small grains sized below 100 nm. Crystalline phase with cubic (disordered) perovskite structure was formed in the samples annealed at a very low temperature (below 500 °C), and well-crystallized thin films were obtained at 700 °C. Although disordered perovskite is dominant in the thin films annealed below 1000 °C, a low volume fraction of 1 : 2 ordering domains was found in the samples and grows with an increase of annealing temperature.

Synthesis and Characterization of AZO Thin Films by Sol-Gel Process: The Influences of Precursors and Dopants

2008 ◽  
Vol 368-372 ◽  
pp. 326-328 ◽  
Author(s):  
M.T. Tsai ◽  
H.C. Chang ◽  
P.J. Tsai
Keyword(s):  
Thin Films ◽  
Zinc Chloride ◽  
Sol Gel ◽  
Film Deposition ◽  
Random Orientation ◽  
Glass Substrates ◽  
Sol Gel Process ◽  
Aluminum Doped Zinc Oxide ◽  
Xerogel Films

Transparent ZnO and aluminum-doped zinc oxide (AZO) thin films were prepared via the sol-gel process on glass substrates using an alcoholic non-polyol route and spin-coater technique for film deposition. Zinc acetate, zinc chloride, and aluminum salt used as cations source. All the undoped and doped xerogel films were amorphous and converted into zincite structure after firing at 200 oC, irrespective of precursor types and dopant amounts. However, the evolution of morphology, microstructure, and texture of the gel films were strongly depended on the precursors and dopants. The films derived from zinc chloride showed strongly preferential (002) orientation, while acetate-derived films exhibited random orientation. On firing at 500 oC, the visible transmittances of films were 50~92%, depending on the kinds of precursors and dopant contents.

The crystallization of thin-film ceramics

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.

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

1999 ◽  
Vol 606 ◽  
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).

Effect of Annealing temperature on the Structural and Magnetic Properties of TbxY3-xFe5O12(x = 0.0, 1.0, 2.0) Thin Films Prepared by Sol-Gel Process

2012 ◽  
Vol 501 ◽  
pp. 236-241 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah ◽  
Ramadan E. Shaiboub
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Garnet Phase ◽  
Sol Gel Process ◽  
Amorphous Structures

Thin films nanoparticles TbxY3-xFe5O12 (x=0.0, 1.0, 2.0) were prepared by the sol-gel process followed by annealing process at various annealing temperatures of 700° C, 800° C and 900° C in air for 2 h. The results obtained from X-ray diffractometer (XRD) show that the films annealed below 900°C exhibit peaks of garnet mixed with small amounts of YFeO3 and Fe2O3. Pure garnet phase has been detected in the films annealed at 900°C. Before annealing the films show amorphous structures. The particles sizes measurement using the field emission scanning electron microscope (FE-SEM) showed that the particles sizes increased as the annealing temperature increased. The magnetic properties were measured at room temperature using the vibrating sample magnetometer (VSM). The saturation magnetization (Ms) of the films also increased with the annealing temperature. However, different behavior of coercivity (Hc) has been observed as the annealing temperature was increased.

Interfacial resistive switching properties of Sr2TiO4/SrTiO3 heterojunction thin films prepared via sol-gel process

2021 ◽  
Author(s):  
Jun Li ◽  
Xin-Gui Tang ◽  
Qiu-Xiang Liu ◽  
Yan-Ping Jiang ◽  
Wen-Hua Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Resistive Switching ◽  
Sol Gel ◽  
Sol Gel Process

An investigation on linear optical properties of dilute Cr doped ZnO thin films synthesized via sol–gel process

2011 ◽  
Vol 509 (30) ◽  
pp. 7854-7860 ◽  
Author(s):  
A. Esmaielzadeh Kandjani ◽  
M. Farzalipour Tabriz ◽  
O. Mohammad Moradi ◽  
H.R. Rezaeian Mehr ◽  
S. Ahmadi Kandjani ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Sol Gel Process ◽  
Linear Optical Properties ◽  
Doped Zno ◽  
Linear Optical

Composition Dependence of Crystallinity for Lead-Free (Li, Na, K)NbO3Powder and Thin Films Fabricated by Sol-Gel Process

2007 ◽  
Vol 358 (1) ◽  
pp. 175-180 ◽  
Author(s):  
Kiyotaka Tanaka ◽  
Ken-Ichi Kakimoto ◽  
Hitoshi Ohsato ◽  
Takashi Iijima
Keyword(s):  
Thin Films ◽  
Composition Dependence ◽  
Sol Gel ◽  
Lead Free ◽  
Sol Gel Process
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