scholarly journals Synthesis and Fabrication of Co1−xNixCr2O4 Chromate Nanoparticles and the Effect of Ni Concentration on Their Bandgap, Structure, and Optical Properties

2021 ◽  
Vol 5 (9) ◽  
pp. 247
Author(s):  
Muhammad Saeed ◽  
Malika Rani ◽  
Kiran Batool ◽  
Hafiza Batool ◽  
Aisha Younus ◽  
...  
Keyword(s):  
Sol Gel ◽  
Parent Compound ◽  
Ceramic Pigment ◽  
Xrd Analysis ◽  
Nickel Concentration ◽  
X Ray Diffraction ◽  
Aqueous Synthesis ◽  
X Ray ◽  
Synthesis Routes ◽  
Sol Gel Synthesis

In the present work, cobalt-chromite-based pigment Co1-xNixCr2O4 chromate powder and nanoparticles with various transition metal concentrations (x = 0.2, 0.4, 0.6, and 0.8) were manufactured by applying aqueous synthesis approaches and sol–gel synthesis routes. XRD analysis of the powder shows that all samples formulated by the sol–gel method were crystalline with a spinel structure. Chromites show green color with a higher nickel concentration, while Co-substituent shows blackish pigments. Samples were annealed at distinct temperatures ranging from 600 °C to 750 °C. The nanoparticles obtained were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy (RS), photoluminescence (PL), and energy-dispersive X-ray spectroscopy (EDS). The particle size of the parent compound (CoCr2O4) ranges from 100 nm to 500 nm, as measured by SEM. The tendency of particles to form aggregates with increasing annealing temperature was observed. These compounds may be successfully used as an effective doped nickel-cobalt ceramic pigment.

scholarly journals Synthesis of lead-based 1212 and 3212 superconductors by an aqueous sol-gel method

2009 ◽  
Vol 7 (3) ◽  
pp. 362-368 ◽  
Author(s):  
Giedre Nenartaviciene ◽  
Ramunas Skaudzius ◽  
Rimantas Raudonis ◽  
Aivaras Kareiva
Keyword(s):  
Sol Gel ◽  
Xrd Analysis ◽  
Structural Features ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
Ceramic Samples ◽  
Xrd Patterns ◽  
Sol Gel Synthesis

AbstractThe aqueous sol-gel synthesis technique for the preparation of (Pb,Sr)Sr2(Y,Ca)Cu2O7±x (Pb-1212) and (Pb2,Cu)Sr2(Y,Ca)Cu2O8±x (Pb-3212) superconductors using two different complexing agents, namely 1,2-ethanediol and tartaric acid was studied. The phase transformations, composition and micro-structural features in the polycrystalline samples were studied by powder X-ray diffraction analysis (XRD), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). XRD analysis of the ceramic samples obtained by calcination of Pb-Sr-Y-Ca-Cu-O acetate-glycolate precursor gels in air, for 10 hours at 800°C and at 825°C, showed the presence of homogeneous Pb-1212 and Pb-3212 crystallites as major phases. The XRD patterns of the ceramics obtained from Pb-Sr-Y-Ca-Cu-O acetate-tartrate precursor gels, however, showed multiphasic character. The critical temperature of superconductivity (TC (onset)) observed by resistivity measurements were found to be 91 K and 75 K for Pb-1212 and Pb-3212 samples, respectively.

scholarly journals Influence of type of precursors on the sol-gel synthesis of the LaCoO3 nanoparticles

2014 ◽  
Vol 22 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Nicoleta Cornei ◽  
Simona Feraru ◽  
Ion Bulimestru ◽  
Andrei Victor Sandu ◽  
Carmen Mita
Keyword(s):  
Crystal Structure ◽  
Sol Gel ◽  
Chelating Agent ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Synthesis ◽  
Perovskite Type ◽  
Type Crystal ◽  
Scanning Electron

Abstract Perovskite-type LaCoO3 was prepared by sol-gel method using nitrates / chlorides as precursors and citric acid as chelating agent. Chemical composition was obtained by means of EDX method. The structures of sintered samples were investigated by scanning electron microscopy (SEM), IR and XRD analysis. The results of X-ray diffraction indicated that the LaCoO3nanopowders obtained using nitrate as precursors had a rhombohedral perovskite-type crystal structure (S. G: R-3c), while that obtained using chloride as precursors had a mixture of LaCoO3, LaOCl and Co3O4. The all lanthanum cobaltites exhibit catalytic activity on the decomposition of hydrogen peroxide, ascribed to their higher surface and Co3+ concentration

scholarly journals Effect of Re and Tm-site on morphology structure and optical band gap of ReTmO3 (Re: La, Ce, Nd, Gd, Dy, Y and Tm: Fe, Cr) prepared by sol-gel method

2018 ◽  
Vol 64 (4) ◽  
pp. 381
Author(s):  
Muhammad Tufiq Jamil ◽  
Javed Ahmad ◽  
Syed Hamad Bukhari ◽  
Murtaza Saleem
Keyword(s):  
Band Gap ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Average Grain Size ◽  
Auto Combustion ◽  
Uv Visible

Rare earth nano sized pollycrystalline orthoferrites and orthocromites ReT mO3 (Re = La, Nd, Gd, Dy, Y and T m = Fe, Cr) have been synthesized by sol-gel auto combustion citrate method. The samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and UV-visible spectroscopy. The samples are single phase as confirmed by XRD analysis and correspond to the orthorhombic crystal symmetry with space group pbnm. Debye Scherer formula and Williamson Hall analysis have been used to calculate the average grain size which is consistent with that of determined from SEM analysis and varied between 25-75 nm. The elemental compositions of all samples have been checked by EDX analysis. Different crystallographic parameters are calculated with strong structural correlation among Re and Tm sites. The optical energy band gap has been calculated by using Tauc relation estimated to be in the range of 1.77 - 1.87 eV and 2.77 - 3.14 eV, for ReFeO3 and ReCrO3, respectively.

scholarly journals Effect of Polymers (PEG and PVP) on Sol-Gel Synthesis of Microsized Zinc Oxide

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Thilagavathi Thirugnanam
Keyword(s):  
Sol Gel ◽  
Cost Effective ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Modifications ◽  
Phase Pure ◽  
Sol Gel Synthesis ◽  
Polyethylene Glycol 6000 ◽  
Granular Morphology ◽  
Scanning Electron

Fibers irregular and seed-like microcrystalline ZnO were synthesized by using a cost-effective and low temperature aqueous sol-gel method. Various polymers, namely, polyethylene glycol 6000 (PEG 6000) and polyvinyl pyrrolidone (PVP), were used as structure directing agents. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The X-ray diffraction pattern revealed the formation of phase-pure ZnO micropowders. It is observed that the polymers play an important role in modifying the surface morphology and the size of the crystallites. A compact granular morphology is observed for the ZnO samples without polymer. The samples exhibit microparticles of size 100 nm for PVP and for PEG-mediated growth, whereas microporous corrugated morphology is observed for added PEG-mediated micropowder. FTIR study is used to confirm the structural modifications occurring in the polymers.

scholarly journals Sol-Gel Synthesis, X-Ray Diffraction Studies, and Electric Conductivity of Sodium Europium Silicate

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ekaterina V. Borisova ◽  
Alexey V. Ignatov ◽  
Eugeni I. Get'man ◽  
Stanislav N. Loboda ◽  
Lyudmyla I. Ardanova ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electric Conductivity ◽  
Rietveld Refinement ◽  
Sol Gel ◽  
Apatite Structure ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Sol Gel Synthesis

Sodium europium silicate, NaEu9(SiO4)6O2, with apatite structure has been obtained and studied using X-ray diffraction and SEM. It has been shown that sodium sublimation does not take place upon synthesis by the sol-gel method. Rietveld refinement has revealed that sodium atoms are ordered and occupy the 4f position. O(4) atoms not related to silicate ions are placed at the centers of Eu(2) triangles. DC and AC electric conductivity and activation energy have been determined for the compound studied.

Sol-Gel Synthesis and Characterization of Nanocrystalline Bi4Ti3O12 Powders

2014 ◽  
Vol 997 ◽  
pp. 359-362 ◽  
Author(s):  
Chun Hong Ma ◽  
Xue Lin ◽  
Liang Wang ◽  
Yong Sheng Yan
Keyword(s):  
Phase Inversion ◽  
Bismuth Titanate ◽  
Sol Gel ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Synthesis ◽  
Source Materials

Nanocrystalline bismuth titanate (Bi4Ti3O12; BTO) powders were successfully prepared by the sol-gel method, using bismuth nitrate (Bi(NO3)3·5H2O) and tetrabutyl titanate (Ti(OC4H9)4) as source materials, acetic anhydride and ethanediol as solvents. The thermal decomposition and phase inversion process of the gel precursors were studied by using differential thermal analysis (DTA). The crystal structures and microstructures of BTO powders were investigated by using x-ray diffraction (XRD), and transmission electron microscope (TEM). The crystallization of amorphous bismuth titanate has been discussed. The effect of sintering temperature on the structure and morphology of BTO was investigated. At 644 oC and above, BTO powder undergoes a phase transformation from tetragonal to orthorhombic. At 900 oC, the purified orthorhombic BTO nanocrystals were obtained.

scholarly journals Influence of ThO2 on the photocatalytic activity of TiO2

2011 ◽  
Vol 9 (6) ◽  
pp. 1027-1038 ◽  
Author(s):  
Radina Kralchevska ◽  
Maria Milanova ◽  
Petya Kovacheva ◽  
Jovo Kolev ◽  
Georgi Avdeev ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
Relative Content ◽  
X Ray Diffraction ◽  
Doping Agent ◽  
X Ray ◽  
Decay Products ◽  
Degradation Rate Constant ◽  
Main Factors ◽  
Sol Gel Synthesis

AbstractMicrocomposites consisting of TiO2 (or Ce-doped TiO2) and ThO2 (0.5–2% of the TiO2 mass) are produced by sol-gel synthesis of TiO2 in presence of ThO2. X-ray diffraction study reveals the effects of ThO2 (compared to the ThO2-free TiO2, obtained by the same method) on the anatase interplanar distances, crystallites size and phase composition. The photocatalytic tests in presence of the composites under UV irradiation reveal an increase of the Malachite Green degradation rate constant. The effect depends on the Th relative content, temperature of annealing of the catalyst and addition of other doping agent. The highest photocatalytic activity is observed for TiO2 obtained at 550°C and containing 1% ThO2. The composite exhibits activity in dark, also. The presence of Ce4+ ions is not an obligatory requirement for the realization of the ThO2 effect. The reported results suggest that the radioactivity of the Th and/or its decay products is one of the main factors responsible for the increased photocatalytic activity of TiO2.

Homogeneity in the Polyether Alkoxide Sol‐Gel Synthesis of YBa2Cu3O7-δ

1994 ◽  
Vol 346 ◽  
Author(s):  
Carol S. Houk ◽  
Gary A. Burgoine ◽  
Catherine J. Page
Keyword(s):  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Mapping Techniques ◽  
Starting Solutions ◽  
Average Size ◽  
Sol Gel Synthesis ◽  
Elemental Maps

ABSTRACTWe have investigated the homogeneity of sol‐gel derived YBa2Cu307‐s from the solution phase to the final product using transmission electron microscopy (TEM), x‐ray diffraction (XRD), and Energy Dispersive X‐ray (EDX) lateral mapping techniques. The starting solutions contain stoichiometric amounts of the metal 2‐(2‐methoxyethoxy)ethoxide components in 2‐(2‐methoxyethoxy)ethanol and appear to be homogeneous by TEM with a uniform distribution of particles having an average size of less than 40 â. Through elemental mapping we see elemental segregation in the high temperature (950 °C) products, which are orthorhombic by XRD. In elemental maps of gel samples fired to 700 °C, which are tetragonal by XRD, we also see elemental inhomogeneity within particles and phase zoning in maps of products from finely ground gels. A comparison of elemental maps and x‐ray diffraction patterns of the products from gel processing and conventional solid state processing is made.

Sol-Gel Synthesis and Characterizations of LiCF3SO3-CeO2 Solid Composite Electrolytes

2010 ◽  
Vol 129-131 ◽  
pp. 506-510 ◽  
Author(s):  
N.A. Dzulkurnain ◽  
N.S. Mohamed
Keyword(s):  
Sol Gel ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Lithium Triflate ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Composite Solid Electrolyte ◽  
Sol Gel Synthesis ◽  
Composite Solid

Composite solid electrolyte systems composed of different compositions of lithium triflate (LiCF3SO3) as host, and cerium oxide (CeO2) as dispersoid were prepared using sol-gel method. The electrical, structural and morphological properties of the composite solid electrolytes were investigated using impedance spectroscopy (IS), X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). Maximum room temperature conductivity was obtained for the system of 60 mol % LiCF3SO3 – 40 mol % CeO2.

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