Top PDF Fabrication and characterization of microlasers by the sol-gel method

Fabrication and characterization of microlasers by the sol-gel method

Fabrication and characterization of microlasers by the sol-gel method

C h a p t e r 2 WHISPERING GALLERY TYPE MICRORESONATORS 2.1 Introduction A wide range of resonator constructed for different applications have been fabricated and investigated. Among them the surface-tension-induced microcavities, such as microsphere and microdisk, attract great interests because unprecedented quality factor (Q) as high as a several billion have been achieved in silica microphere, which are of great use for ultra- narrow linewidth, cavity QED, ultra-low threshold microlasers, and other photonics application. The microsphere, together with cavities with circular geometry, is called Whispering Gallery Mode (WGM) resonators. The WGM is named after the sound effect noted in some cathedrals, where one can whisper along the wall and hear all along the inside perimeter of the dome. Light presents the same behavior when injected tangentially into the WGM type cavities, where light is trapped in circular orbits just within the surface by repeated total internal reflections. This low dissipation mechanism for confinement leads to unusual high quality factor mentioned above.
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Fabrication and Optical Characterization of Zinc Oxide Nanoparticles Prepared via a Simple Sol-gel Method

Fabrication and Optical Characterization of Zinc Oxide Nanoparticles Prepared via a Simple Sol-gel Method

In this research zinc oxide (ZnO) nano-crystalline powders were prepared by sol-gel method using zinc acetate. The ZnO nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis), Fourier transform infra-red (FT-IR) and energy dispersive X-ray (EDX) spectroscopy. The structure of nanoparticles was studied using XRD pattern. The crystallite size of ZnO nanoparticles was calculated by Debye– Scherrer formula. Morphology of nano-crystals was observed and investigated using the SEM. The grain size of zinc oxide nanoparticles were in suitable agreement with the crystalline size calculated by XRD results. The optical properties of particles were studied with UV-Vis an FTIR absorption spectrum. The Raman spectrum measurements were carried out using a micro-laser Raman spectrometer forms the ZnO nanoparticles. At the end studied the effect of calcined temperature on the photoluminescence (PL) emission of ZnO nanoparticles.
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Application of the sol-gel method at the fabrication of PLZT:Yb3+ ceramics

Application of the sol-gel method at the fabrication of PLZT:Yb3+ ceramics

Such obtained powders were subsequently pressed into pellets, and sintered by the free sintering method at temperature T = 1250°C / 6h. The morphology of fabricated PLZT:Yb 3+ ceramic powders and samples was studied using Scanning Electron Microscopy. Chemical characterization of samples was carried on using the Energy-dispersive X-ray spectroscopy - EDS system. Studies provided detailed data concerning the relationships between doping and preparing conditions on the basic physical and chemical properties of obtained ceramic materials.

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SYNTHESIS OF NANOSTRUCTURED MAGNESIUM OXIDE BY SOL GEL METHOD AND ITS CHARACTERIZATION

SYNTHESIS OF NANOSTRUCTURED MAGNESIUM OXIDE BY SOL GEL METHOD AND ITS CHARACTERIZATION

Various fabrication techniques are also employed to synthesize MgO nanoparticles having their own advantages and disadvantages 12 . Spherical shaped magnesium oxide nanoparticles were synthesized successfully by sol-gel method using magnesium nitrate and sodium hydroxide 13 . A sol-gel method is an important technique for the formation of magnesium hydroxide followed by annealing at room temperature to form MgO. After synthesis of MgO nanoparticles, the study of structural, morphological and optical properties was carried out by using techniques such as XRD, FTIR, TEM and UV visible spectroscopy. The present work was aimed to synthesis of MgO nanoparticles chemically and their characterization at room temperature.
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Preparation and Characterization of Nano-TiO 2 Thin Films by Sol-gel Dip-coating Method

Preparation and Characterization of Nano-TiO 2 Thin Films by Sol-gel Dip-coating Method

Inagaki et al., (2001) have prepared stable anatase- TiO 2 by sol-gel method using TiOSO 4 as a starting material and followed by calcination at 700°C to 1100°C and found that anatase-TiO 2 fine powder was stable up to 800°C. Ge et al. (2006) have synthesized nano-TiO 2 thin films on glass slide substrates by sol-gel dip-coating method using titanyl sulfate (TiOSO 4 •nH 2 O, 23.2% TiO 2 ) followed by drying in air oven from 100°C to 300°C, relatively low temperature. In this work, we demon- strate the fabrication of anatase nano-TiO 2 thin films by sol-gel dip-coating method using titanium tetraisopropoxide as a starting material and discuss the effects of calcination temperatures on the structure and properties of the nanocrystalline TiO 2 thin films.
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Fabrication of high temperature piezoelectric ceramics by sol gel method

Fabrication of high temperature piezoelectric ceramics by sol gel method

The end of the probe was plugged with a Macor fitting that acted as both a platform for the sample and a fitting for attaching wires to the sample [7]. Two copper wires were threaded through dual-bore alumina tubes down the centre of the probe, to electrically insulate them from each other and from the probe itself. The wires were then threaded through holes in the Macor fitting to bring them in contact with the sample. The wire was clamped to the sample to provide good electrical contacts for the high voltage. Prior to the poling attempts the samples were sputter coated on both sides with a gold-palladium electrode. The initial operational temperature of this method was 700°C, above the Curie temperature of bismuth titanate, with the temperature decreasing while the field was maintained. The plan was that, initially, poling would be attempted with a voltage in the region of 5 kV on samples between one and two millimetres thick, with modifications being made based on the quality of the poling.
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Synthesis and Characterization of NiO Nanoparticles by Sol Gel Method

Synthesis and Characterization of NiO Nanoparticles by Sol Gel Method

Numerous new techniques have been developed for the preparation of NiO nanoparticle, such as sol­gel method, ultrasonic radiation, pyrolysis by microwave, hydrothermal synthesis, precipitation­calcination method, carbonyl meth- od, laser chemical method, mechanochemical processing, microemulsion method, flame spray pyrolysis, solid-state method, and so forth. 28­32) Among them, the chemical method of sol­gel preparation is one of the simplest and lowest-cost techniques for preparing pure transition metal oxides with relatively high speci fi c surface area at low temperature. 33­35) By selecting a proper precursor and
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Synthesis By Sol Gel Method And Characterization Of Co3O4 Nanoparticles.

Synthesis By Sol Gel Method And Characterization Of Co3O4 Nanoparticles.

Department of Physics,P.R.Patil Institute of Polytechnic & Technology,Amravati,India S.D.Thakre 3 Department of Physics,Dr.rajendra Gode Institute of Technology& Research,Amravati,India Abstract- A Co 3 O 4 nanoparticles was synthesized by sol gel technique employed with appropriate reactants.in this case, we used metal salt and Tetrahydrofuran (THF) as starting material and the obtained product were calcined at 500 0 C & 550 0 C.the prepared nanoparticles were characterized by XRD, SEM, EDAX . Particle structure was confirmed by x-ray diffraction analysis; size was determined by Scherrer formula. SEM analysis showed that prepared nanoparticles were in Nano regime, somewhat round shaped and interlinked with each other. EDAX analysis showed that composition obtained was near stoichiometry.
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Preparation and characterization of magnetite (Fe3O4) nanoparticles by sol gel method

Preparation and characterization of magnetite (Fe3O4) nanoparticles by sol gel method

Received 18 March 2018; Revised 12 July 2018; Accepted 29 July 2018 ABSTRACT The magnetite (Fe 3 O 4 ) nanoparticles were successfully synthesized and annealed under vacuum at different temperature. The Fe 3 O 4 nanoparticles prepared via sol-gel assisted method and annealed at 200-400ºC were characterized by Fourier Transformation Infrared Spectroscopy (FTIR), X-ray Diffraction spectra (XRD), Field Emission Scanning Electron Microscope (FESEM) and Atomic Force Microscopy (AFM). The XRD result indicate the presence of Fe 3 O 4 nanoparticles, and the Scherer`s Formula calculated the mean particles size in range of 2-25 nm. The FESEM result shows that the morphologies of the particles annealed at 400ºC are more spherical and partially agglomerated, while the EDS result indicates the presence of Fe 3 O 4 by showing Fe-O group of elements. AFM analyzed the 3D and roughness of the sample; the Fe 3 O 4 nanoparticles have a minimum diameter of 79.04 nm, which is in agreement with FESEM result. In many cases, the synthesis of Fe 3 O 4 nanoparticles using FeCl 3 and FeCl 2 has not been achieved, according to some literatures, but this research was able to obtained Fe 3 O 4 nanoparticles base on the characterization results.
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SYNTHESIS AND CHARACTERIZATION OF NICKLE-OXIDE NANOPARTICLES BY SOL-GEL METHOD

SYNTHESIS AND CHARACTERIZATION OF NICKLE-OXIDE NANOPARTICLES BY SOL-GEL METHOD

Nickle oxide (NiO) nanoparticles have been synthesized via modified Sol-gel method. Sol-gel technique is modified in such a way that it becomes simple and low cost synthesis technique. In this modified method, oxalic acid was replaced with citric acid which was mixed with ethylene glycol to form a homogenous gel. Here we replaced ethyl alcohol with ethylene glycol. Ethylene glycol here acted as a sol stabilizer. The metal nanoparticles were characterized by XRD, UV-Vis and FT-IR spectroscopy. The results obtained from XRD, UV-Vis and FT-IR spectra analysis confirms the formation of nickle oxide nanoparticles.
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Synthesis and Characterization of Silver-oxide Nanoparticles by Sol-Gel Method

Synthesis and Characterization of Silver-oxide Nanoparticles by Sol-Gel Method

1 Material Science & Electrochemistry Lab., Dept. of Chemistry, Chaudhary Devi Lal University, Sirsa (Haryana) (India) ABSTRACT Silver oxide (Ag 2 O) nanoparticles were synthesized via modified Sol-gel method. Sol-gel technique is very simple and low cost synthesis technique. In this modified method, oxalic acid was replaced with citric acid which was mixed with ethylene glycol to form a homogenous gel. Here we replaced ethyl alcohol with ethylene glycol. Ethylene glycol here acted as a sol stabilizer. The metal nanoparticles were characterized by XRD, UV- Visible and FT-IR spectroscopy. The results obtained from XRD, UV-Visible and FT-IR spectral analysis confirms the formation of silver oxide nanoparticles. Thermal and optical study of metal nanoparticles was also carried out using TGA/DTA and Tauc plot methods.
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Preparation and Characterization of SiO2-CaCl2 Nanocomposite by the Sol-Gel Method

Preparation and Characterization of SiO2-CaCl2 Nanocomposite by the Sol-Gel Method

(Received: April 6, 2008 – Accepted in Revised Form: July 2, 2009) Abstract The SiO 2 -CaCl 2 hybrid porous materials were prepared by the sol-gel method. This process was conducted by the hydrolysis and condensation of Tetraethyl orthosilicate (TEOS) by replacement of ethanol from alcogel and drying at the ambient temperature to obtain xerogel structure. The alcogel samples were synthesized from TEOS, EtOH, H 2 O, HCl, NH 4 OH and CaCl 2 , while the total molar ratio of the compounds was 1: 9: 4: 8 x 10 -4 , 8 x 10 -3 , respectively. Xerogel containing 30 wt % of CaCl 2 (dry matter) was prepared and characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Furier Transmittance Infra Red spectrum (FT-IR), Energy Dispersive X-ray (EDX) and Thermal Gravimetric Analysis (TGA ) systems. The results obtained from SEM and EDX showed the micrograph of CaCl 2 on the silica and chemical elemental analysis, respectively. On the other hand, The TEM micrograph confirmed average particle size of SiO 2 -CaCl 2 about 50 nm and FT-IR spectrum described the functional groups of the nanocomposite. The thermal analysis of SiO 2 -CaCl 2 nanocomposite was performed using TGA system and the results showed that the suitable temperature for initial thermal treatment was about 200˚C.
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Synthesis and characterization of Eu:CaTiO3 nanopowder by using sol gel method

Synthesis and characterization of Eu:CaTiO3 nanopowder by using sol gel method

b Assistant professor of Physics, Govt. Arts & science College, Komarapalayam - 638183, India. E.mail: anjelin1980@gmail.com a Abstract- The main work is to synthesize perovskite type of Eu doped CaTiO 3 nanopowder using sol-gel method. The as-synthesized sample was characterized by various highly developed techniques. The Structural analysis was calculated by using X-ray Diffraction Method (XRD). The functional groups were examined by using Fourier Transform Infrared Spectrophotometer (FTIR). The Surface structure was examined by Scanning Electron Microscopy (SEM). The elemental configuration was calculated by Energy Dispersive X-Ray Spectroscopy (EDAX) . The optical property was obtained by Ultra - Violet visible Infrared Spectroscopy (UV-vis DRS), and the Microstructure analysis were performed by using high resolution transmission electron spectroscopy (HRTEM).
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Synthesis and characterization of the Pt/SiO2 nanocomposite by the sol-gel method

Synthesis and characterization of the Pt/SiO2 nanocomposite by the sol-gel method

The silica supported platinum nanoparticles was synthesized by using the sol-gel method. The possibility of using diamminedinitro platinum(II) as Pt precursor and effect of metal precursor concentration on the final Pt nanoparticle size was investigated. A stable silica sol was prepared via hydrolysis of tetraethyl ortho- silicate (TEOS) as a metal alchoxide and condensation reaction. Subsequently, diamminedinitro platinum (II) was added to sol to form the Pt/silica sol. After drying and calcination of the sol, the Pt/SiO2 nanocpmposite has been obtained. Crystallographic information and crystalline size of the synthesized Pt/SiO 2 were
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Preparation and Characterization of TiO2 Nanoparticles Prepared by Sol-Gel Method

Preparation and Characterization of TiO2 Nanoparticles Prepared by Sol-Gel Method

stirring times are shown in Fig. 3. The XRD characteristic peaks revealed that, the main phases of all three samples were anatase and rutile phases. Furthermore, no significant difference was observed between them indicating that, the increase in stirring time does not affect the crystal structure of the final product. The crystalline size of nanopowders was calculated according to Scherer equation as shown in Table 2. It was observed that by the increase of stirring time to 36 h the crystallite size decreased. However, further increase of stirring time increased the crystallite size due to the agglomeration of nanoparticles. Takahashi and Yamaguchi [19] found that during stirring of a solution, the viscosity increased, therefore the particle size improved, however, due to the spinner revolution, the particle size decreased. So that with increasing the stirring time from 12 h to 36 h the crystallite size decreased. As it proceeded, after 36 h, more water evaporated from the sol, thus the supersaturated solution supplied the material necessary to bond colliding particles and form agglomerates. Moreover, this effect was probably due to Brownian forces that led to particle aggregation [18,28]. In addition, heat generated in the longer stirring time might be playing a factor in enhancing the movement of particles and particle aggregation [29]. Novakovic and Korthaus [19] have reported that drying of the sol invariably leads to agglomeration because the residual salts present in the sol form solid bridges between particles as the water evaporates.
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PREPARATION AND CHARACTERIZATION OF MAGNETITE NANOPARTICLES BY SOL-GEL METHOD FOR WATER TREATMENT

PREPARATION AND CHARACTERIZATION OF MAGNETITE NANOPARTICLES BY SOL-GEL METHOD FOR WATER TREATMENT

Abstract:Environmental pollution such as dyes has been excessively released into the environment and has created a major global concern. Congo Red is a benzidine-based anionic diazo dye with two azo groups. It is toxic to many organisms and is a suspected carcinogen and mutagen. The presence of Congo Red (CR) in water even at very low concentration is highly visible and undesirable. Present work is focused on synthesis of magnetite nanoparticles which showed a high adsorption capacity of Congo Red and is useful in removal of CR from wastewater. Magnetite (Fe 3 O 4 ) nanoparticles have been successfully synthesized by SolGel method by using Ferric nitrate (Fe (NO 3 ) 3 .9H 2 O) and Ethylene glycol (C 2 H 6 O 2 ) as precursors in different annealing temperatures. The obtained nanoparticles have been characterized by X-Ray diffraction (XRD), Scanning Electron Microscope (SEM), X-ray energy dispersive spectrometer (EDS) and Particle Size Analyzer. XRD measurements indicate that the obtained nanoparticles are single phase and the particle size increased by increasing the temperature.
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Synthesis and Characterization of AlyCu0.15Zn0.85-yFe2O4 Ferrite Prepared by the Sol-Gel Method

Synthesis and Characterization of AlyCu0.15Zn0.85-yFe2O4 Ferrite Prepared by the Sol-Gel Method

The properties of these materials essentially depend on their structure, size and shape, which are highly determined by the sintering process, synthetic processes, and the type and amount of constituent elements or additives [9]. In this research, we report the preparation of nanoparticles of Al y Cu 0.15 Zn 0.85-y Fe 2 O 4 ferrites (where y = 0.15, 0.3, 0.45, 0.6, 0.75) by using the solgel combustion technique. The prepared ferrites were investigated by XRD, SEM and EDX. The structural and dielectric properties of nanoparticles ferrites were studied.
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Synthesis and Characterization of TIO2 Nano Powder Using SOL GEL Method

Synthesis and Characterization of TIO2 Nano Powder Using SOL GEL Method

III. RESULTS AND DISCUSSION A. Powder Preparation of TiO 2 Nanomaterials Exothermic reactions were observed when 5 ml of TiCl 4 solution was added to 100 ml of deionized water under fume hood. While adding ammonium hydroxide a white precipitate was observed and the yellow gel rose obtained. The formation of Ti(OH) 4 were indicated when gel being yellow in colour. The gel was stirred using magnetic stirrer for an hour and allowed to settle for a day precipitation were formed and the precipitate was centrifuged. The centrifuged precipitations were dried at 150 o C for 6 hours, which leads to form white amorphous TiO 2 when cooling to room temperature. The product was placed in oven at 150°C, 350°C and 550°C for 5 hours to calcinate. Due to calcination process white TiO 2 were formed. The products were cooled to room temperature and crushed using agate mortar. Finally, physical grinding method is adopted in this method to reduce the size of TiO 2 powder. The product material was taken into a grinding machine which having rotator with high rpm and it grinded and crushed well for 30 minutes with precaution to avoid any contamination. Thus the powdered materials subjected to different calcination temperatures of 150°C, 350°C and 550°C respectively.
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Synthesis and characterization of Tianium dioxide nanorod by anodization and  Sol-gel method

Synthesis and characterization of Tianium dioxide nanorod by anodization and Sol-gel method

Finally, the substrate was involved pore wieding step by using 1M NaOH solution for 2 minits [28] . 2.1.2. Synthesis of Titaniam nanorod Titanium nanorod was prepared by sol- gel method. Aluminium template immersed in 3:1 ratio of Titanium isopropoxide and ethanol mixture. The sample was filtered by using vaccum filteration and dried at room temperature for 12 hrs. Then the prepared compound was calcinated at 500 ºC. The resulting titanium nanorod was obtained.

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Synthesis And Characterization of Zno-Nanorods By Sol-Gel Method For White Led Phosphors

Synthesis And Characterization of Zno-Nanorods By Sol-Gel Method For White Led Phosphors

Chandar Rao. P 1* , Sreelatha C. J. 1 and Ravinder G. 1 1 Dept. Of Physics, Kakatiya University, Warangal-506009, Telangana State, India ABSTRACT We have well chemically synthesized the ZnO nanorods via sol-gel method showing broad luminescence in the visible wavelength range. Their lengths and diameters were 1um and 100nm respectively. X-ray diffraction results revealed that the synthesized ZnO product was highly crystalline having hexagonal wurtzite structure. The photoluminescence (PL) spectroscopy was taken by exciting the ZnO nanorods with the He-Cd laser it has one peak, the peak intensity of the near band edge luminescence at 480nm .After the luminescence peak ranges from 400-800 nm and it is broad enough to be used as a phosphor for a white LEDs. The LED shows a white light emission and the electroluminescence measurement show a strong enlargement blue LED current.
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