X-rays to study, induce, and pattern structures in sol–gel materials

2009 ◽  
Vol 57 (3) ◽  
pp. 236-244 ◽  
Author(s):  
Paolo Falcaro ◽  
Plinio Innocenzi
Keyword(s):  
Sol Gel ◽  
X Rays ◽  
Pattern Structures

Structural, optical and other spectral studies of transition metal Ti4+-doped Zn-Cd oxide nanomaterials

2020 ◽  
Vol 34 (06) ◽  
pp. 2050033 ◽  
Author(s):  
Mohd Saleem ◽  
S. Tiwari ◽  
M. Soni ◽  
N. Bajpai ◽  
Ashutosh Mishra
Keyword(s):  
Sol Gel ◽  
Relaxation Times ◽  
Hexagonal Structure ◽  
Spectral Studies ◽  
X Rays ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
Spectroscopy Analysis ◽  
Auto Combustion ◽  
High Dielectric

Titanium ([Formula: see text])-doped nanoparticles of the type [Formula: see text] [[Formula: see text], [Formula: see text]] are reported in this study. The samples were synthesized by citric acid assisted sol–gel auto combustion (SGAC) method. The samples are characterized by X-ray diffraction (XRD), Raman, Field emission scanning electron microscopy (FESEM), Energy dispersive analysis of X-rays (EDAX) and Fourier transform infra-red (FTIR) techniques for structural studies. Further, for optical properties, UV-Vis technique has been used. In addition, samples were studied for dielectric properties. Room-temperature XRD data study reveals the sample formation with wurtzite hexagonal structure exhibiting space group [Formula: see text]mc also confirmed from Rietveld refinement of XRD data. Raman spectra displays characteristic active phonon modes in pristine [Formula: see text] and doped [Formula: see text]. UV-Vis diffused reflectance spectroscopy analysis infer bandgap values of 3.14 and 3.12 eV for [Formula: see text] and [Formula: see text], respectively. The dielectric studies confirmed high dielectric constant for [Formula: see text] compared to pristine [Formula: see text]. A non-Debye character with spread of relaxation times was witnessed from impedance study.

Effect of Rb+ -Doping on the Crystallization, Phase Transition and Photocatalytic Activity of Nanosized TiO2 Catalyst

2012 ◽  
Vol 476-478 ◽  
pp. 954-957 ◽  
Author(s):  
Zhao Hui Ni ◽  
Xiao Li Kou ◽  
Xin Yu Ding ◽  
Cun Wang Ge ◽  
Xiao Hui Jing
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Surface Area ◽  
Sol Gel ◽  
Rutile Phase ◽  
Bet Surface Area ◽  
X Rays ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Kinetics Of

In order to study the ion effect on titania phase structure, crystallite size, and photocatalytic activity, Rb+-doped TiO2 nanoparticles were prepared via a modified sol-gel method and characterized by means of X-ray diffraction, Energy Dispersive X-rays spectroscopy and transmission electron microscopy. The photocatalytic activity of the elaborated powders was studied following the degradation of methyl orange. The results indicate that doping Rb+ increases the BET surface area of TiO2 crystals, decreases the crystal size, reduces the diminishing rates of surface area with increasing calcinations temperature, raises the temperature at which anatase changes into rutile phase, and so significantly increases the photocatalytic activity of TiO2. The kinetics of the methyl orange degradation fits Langmuir-Hinshelwood kinetics model well.

scholarly journals Enhanced bioactivity of Pure ZnO and ZnO-Ag nanocomposite Using Sol-Gel method for Self-Cleaning Application

2019 ◽  
Vol 10 (4) ◽  
pp. 3649-3656 ◽  
Author(s):  
Azhar J. Bohan ◽  
Ghaed K. Salman ◽  
Duha S. Ahmed
Keyword(s):  
Sol Gel ◽  
Heat Rate ◽  
Ammonia Solution ◽  
Morphological Properties ◽  
Plate Count ◽  
X Rays ◽  
Gram Negative ◽  
Gel Method ◽  
Sol Gel Method ◽  
Gram Negative Organisms

In the current study, Pure ZnO and Ag-ZnO nanocomposite are established using the sol-gel method with the influence of ammonia solution NH4OH to incorporate Ag ions into ZnO and form Ag-ZnO nanocomposites. Then pure ZnO and Ag-ZnO nanocomposites were annealed at 450oC for tow h in a muffle furaning using temperture controlling, and heat rate was set at temperature 100oC per min. The structural and morphological properties of samples were characterized using XRD, FTIR, and FESEM with Energy dispersive X-rays (EDX). In addition, the antibacterial activity of pure ZnO and Ag- ZnO nanocomposite was evaluated against gram-positive and gram-negative organisms by plate count test. The results of the test revealed strong antibacterial behavior of nanocomposite against bacteria as compared to pure ZnO and improved efficiency of incorporation Ag ion on ZnO.

scholarly journals Comparison between the UV and X-ray Photosensitivities of Hybrid TiO2-SiO2 Thin Layers

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3730
Author(s):  
Maxime Royon ◽  
Francis Vocanson ◽  
Damien Jamon ◽  
Emmanuel Marin ◽  
Adriana Morana ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Sensors ◽  
Light Emitting Diode ◽  
Sol Gel ◽  
Dip Coating ◽  
Thin Layers ◽  
Light Sources ◽  
X Rays ◽  
X Ray ◽  
The Impact

The photo-induced effects on sol–gel-based organo TiO2-SiO2 thin layers deposited by the dip-coating technique have been investigated using two very different light sources: A light-emitting diode (LED) emitting in the UV (at 365 nm, 3.4 eV) and an X-ray tube producing 40 keV mean-energy photons. The impact of adding a photo-initiator (2,2-dimethoxy-2-phenylacetophenone-DMPA) on the sol–gel photosensitivity is characterized namely in terms of the photo-induced refractive index measured through M-line spectroscopy. Results show that both silica-titania sol–gel films with or without the photo-initiator are photosensitive to both photon sources. The induced refractive index values reveal several features where slightly higher refractive indexes are obtained for the sol–gel containing the photo-initiator. UV and X-ray-induced polymerization degrees are discussed using Fourier-transform infrared (FTIR) spectroscopy where the densification of hybrid TiO2-SiO2 layers is related to the consumption of the CH=C groups and to the decomposition of Si-OH and Si-O-CH3 bonds. X-rays are more efficient at densifying the TiO2-SiO2 inorganic and organic network with respect to the UV photons. Hard X-ray photolithography, where no cracks or damages are observed after intense exposition, can be a promising technique to design submicronic-structure patterns on TiO2-SiO2 thin layers for the building of optical sensors.

Study On Nano-Structured SnO2-23wt%TiO2-21wt%RuO2 Coated Titanium Anode

2006 ◽  
Vol 118 ◽  
pp. 603-608
Author(s):  
Xin Wang ◽  
Dian Tang ◽  
Jing En Zhou
Keyword(s):  
Electron Microscope ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
Oxide Coating ◽  
Rutile Phase ◽  
O2 Evolution ◽  
Ternary Oxide ◽  
Nominal Composition ◽  
X Rays ◽  
High Level

Sn is one of the most important elements for the Cl2-evolving anode coatings, but it always used as a minor additive. In this paper, an Sn-based ternary oxide coating with its composition of SnO2-23wt%TiO2-21wt%RuO2 was prepared by a sol-gel technique through etching, painting, sintering and annealing. The differential thermal analysis (DTA) shows that the crystallization behavior of the ternary xerogel is more similar to that of pure xerogels SnO2. X-rays diffraction (XRD) indicates that the coating is composed of rutile phase (Sn,Ti,Ru)O2. Any other undesired phases, for example, anatase TiO2 and metallic ruthenium phases are not found in the coatings. The microstructure and the morphologies were studied by a transmission electron microscope (TEM) and a scanning electron microscope (SEM). The results of energy dispersive spectrometer (EDS) indicate Sn content in the coatings remain at high level and coincident with the nominal composition. The grain sizes in the coatings are around 4 nm. The voltage of Cl2-evolution and O2-evolution shows the ternary coating has good electrochemical properties.

Preparation and Characterization of NiO Nanoparticles

2015 ◽  
Vol 31 ◽  
pp. 93-102 ◽  
Author(s):  
Farrakh Shahzad ◽  
Karl Ettinger ◽  
Ilse Letofsky-Papst ◽  
Julia Weber ◽  
Peter Knoll
Keyword(s):  
Crystallite Size ◽  
Calcination Temperature ◽  
Ph Value ◽  
Sol Gel ◽  
Systematic Change ◽  
X Rays ◽  
Nio Nanoparticles ◽  
Calcination Time ◽  
Transmission Electron

NiO nanoparticles are successfully prepared by sol-gel technique. A systematic change in preparation parameters like calcination temperature, calcination time and pH value has been done in order to study the influence on crystallite size. The prepared samples are characterized by X-ray diffractometer, Transmission electron microscopy, Energy dispersive x-rays analysis and Raman spectroscopy. It is shown that crystallite size mainly depends on the calcination temperature rather than pH value or calcination time.

scholarly journals Complex correlations between microstructure and magnetic behavior in SrFe12O19 hexaferrite nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pierfrancesco Maltoni ◽  
Sergey A. Ivanov ◽  
Gianni Barucca ◽  
Gaspare Varvaro ◽  
Davide Peddis ◽  
...  
Keyword(s):  
Permanent Magnets ◽  
Profile Analysis ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Line Profile Analysis ◽  
X Rays ◽  
Hard Magnetic Materials ◽  
Tem Analysis ◽  
Complex Relation ◽  
Transmission Electron

AbstractThe magnetic properties of SrFe12O19 (SFO) hard hexaferrites are governed by the complex relation to its microstructure, determining their relevance for permanent magnets´ applications. A set of SFO nanoparticles obtained by sol–gel self-combustion synthesis was selected for an in-depth structural X-Rays powder diffraction (XRPD) characterization by means of G(L) line-profile analysis. The obtained crystallites´ size distribution reveal a clear dependence of the size along the [001] direction on the synthesis approach, resulting in the formation of platelet-like crystallites. In addition, the size of the SFO nanoparticles was determined by transmission electron microscopy (TEM) analysis and the average number of crystallites within a particle was estimated. These results have been evaluated to illustrate the formation of single-domain state below a critical value, and the activation volume was derived from time dependent magnetization measurements, aiming to clarify the reversal magnetization process of hard magnetic materials.

Optical Properties of Sol-Gel Derived PbTiO3 and PbZr1−xTiO3 Ferroelectric Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
Xiangjian Meng ◽  
Zhiming Huang ◽  
Hongjian Ye ◽  
Jiangong Cheng ◽  
Pingxiong Yang ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Wavelength Region ◽  
Ferroelectric Thin Films ◽  
Silicon Substrates ◽  
X Rays ◽  
Phonon Modes ◽  
Infrared Reflection Spectroscopy

AbstractWith sol-gel processing and rapid thermal annealing (RTA), crack-free PbTiO3 and PbZr1−xTixO3(x=0.2-0.8) ferroelectric thin films were prepared on Si(100) and Pt/Ti/SiO2/Si(100) substrates respectively. Results from x-ray diffraction (XRD) show that the films are single perovskite phase structure. Scanning electron microscopy (SEM) was used to determine the grain sizes of the thin films. Energy dispersive spectroscopy (EDS) of x rays was used to analyze the composition of the films. From infrared reflection spectroscopy in the wavelength region of 40-700 cm−1 at 300K, the vibrational mode frequencies in PbTiO3 thin films on silicon substrates were obtained at the wavenumbers of 79, 155, 206, 298, 344, 461, 520 and 621 cm−1. Among these phonon modes, the modes at 298 and 461 cm−1 have not been reported before. The infrared optical constants and the thickness of PZT thin films on Pt/Ti/SiO2/Si(100) substrates were directly measured in the wavelength region of 2-12μm by an automatic wavelength swept infrared spectroscopic ellipsometer. These constants include: refractive index (n), extinction coefficient (k), thickness of the films and absorption coefficient (α). Possible correlation among the processing, microstructure and optical properties of the thin films were discussed.

Cobalt doping of nickel ferrites via sol gel approach: effect of doping on the structural and dielectric properties

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Farzana Majid ◽  
Seemab Dildar ◽  
Sadia Ata ◽  
Ismat Bibi ◽  
Ijaz ul Mohsin ◽  
...  
Keyword(s):  
Lattice Constant ◽  
Metal Ion ◽  
Structural Parameters ◽  
Sol Gel ◽  
Raman Shift ◽  
Tangent Loss ◽  
X Rays ◽  
Cobalt Doping ◽  
Cobalt Ions ◽  
Cobalt Substitution

Abstract Cobalt doped nickel ferrites were fabricated by sol gel route and the dielectric constant, tangent loss and AC conductivity were investigated as a function of Co doping. The X-ray diffractometer characterization confirmed that the Co x Ni1−x Fe2O4 with doping concentration (x = 0.1, 0.2, 0.3, 0.4, and 0.5) have cubic spinel structure. In the XRD spectrum there appear extra peaks of Fe2O3 as an impurity that is gradually disappear by increasing doping ratio of cobalt ions, which is an indication of high crystallinity. The structural parameters (lattice constant, grain size, dislocation density, X-rays density and packing factor) are greatly influenced by the doping of cobalt atoms i.e., lattice constant increases. The crystal size increases from 30 to 42.26 nm by cobalt substitution in the pure nickel ferrites. The Fourier Transform IR Spectroscopy indicate shift in peaks to lower frequency region because cobalt doping reduced binding energy between metal ion and oxygen ions. Atomic structure of cobalt doped nickel ferrites examined by the Raman spectroscopy. Co x Ni1−x Fe2O4 shows Raman mode at ∼285, ∼477, ∼563, ∼624 and ∼704 cm−1. There is unnoticeable Raman shift due to the doping of cobalt’s atoms.

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