scholarly journals Synthesis and Characterization of Lanthanum Oxide La2O3 Net-like Nanoparticles By New Combustion Method

2021 ◽  
Vol 12 (3) ◽  
pp. 3066-3075

Herein is a new procedure to synthesize lanthanum oxide (La2O3) nanoparticles, which is eco-friendly and simple. The La2O3 nanoparticles were prepared by sol-gel method using modification in time of stirring, type of PEG, and temperature of the reaction. Scherer's formula was used to estimate the average crystallite of La2O3 nanoparticle size from X-ray diffraction peaks of powder. The measured average particle size of La2O3 nanoparticles using the major signals of the X-ray diffraction spectrum after calcination was 37 nm. Fourier Transform Infrared Spectroscopy technique was done to analyze the chemical structure of synthesized materials. The surface morphology of obtained nanoparticles was also studied by SEM and AFM techniques. Thermal gravimetric analysis was investigated by Thermogravimetric analysis (TGA) to confirm the thermal stability of synthesized nanoparticles.

Author(s):  
Ramesh N. Taikar ◽  
Sadanand R. Sarve ◽  
Disha T. Yele ◽  
Deepak R. Taikar ◽  
Kalpana R. Nagde

Nano Ni-Zn ferrite with composition Ni 0.6 Zn 0.4 Fe2O4 is prepared by using sol-gel auto-combustion method with citric acid as a fuel. The structural properties of synthesized nano-ferrite is characterized by powder X-ray diffraction (XRD) technique while the electrical properties have been studied using two probe method. The X-ray diffraction study confirms that, there is a formation of single-phase cubic spinel with most intense peak at [311] having lattice constant of 8.3585 A0 and the average particle size is found to be 45.63 nm. In addition to this, the electrical resistivity of Ni-Zn Ferrite decreases with increase in temperature which exhibits semiconductor nature.


2008 ◽  
Vol 8 (3) ◽  
pp. 1199-1202 ◽  
Author(s):  
Li Qing Yue ◽  
Fu Jun Zhang ◽  
Jin Zhao Huang ◽  
Li Wei Wang

The sol–gel method was used to obtain a kind of white-light emitting ZnS:Mn2+ nanoparticles capped by methacrylic acid with an average particle size of ∼7nm. The photoluminescence spectra, X-ray diffraction spectra, Fourier transform infrared reflection spectra and ultraviolet absorption spectra were used to measure their optical properties and crystal structures. The ZnS:Mn2+ nanoparticles with 0.58 wt% Mn2+ concentration emitted white light when excited by 380 nm. The PL spectrum exhibits two emission peaks under irradiation: one at 480 nm generated from the ZnS matrix, and one at 590 nm emitted by the doped Mn2+ ions. The nanoparticles will only emit white light with the optimum Mn2+ concentration (0.58 wt%). X-ray diffraction demonstrates the synthesized ZnS:Mn2+ nanoparticles have zinc blend crystal structure, and the infrared patterns of the capped ZnS:Mn2+ nanoparticles and methacrylic acid are comparable, indicating that the methacrylic polymer has capped or modified ZnS:Mn2+ nanoparticles.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
J. F. Bozeman ◽  
H. Huang

Cu-Pt bimetal catalysts supported on nanocrystalline CeO2(nano-ceria) are synthesized via the low-cost sol-gel approach followed by impregnation processing. The average particle size of the catalytic composites is 63 nm. Ceria nanopowders sequentially impregnated in copper solution and then in Pt solution transformed into Pt-skin-structured Cu-Pt/ceria nanocomposite, based on the surface elemental and bulk compositional analyses. The ceria supporter has a fluorite structure, but the structure of Cu and Pt catalytic contents, not detected by X-ray diffraction spectroscopy due to the low loading level, is yet conclusive. The bimetallic catalytic nanocomposites may potentially serve as sulfur-tolerant anode in solid oxide fuel cells.


Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 274-281 ◽  
Author(s):  
S. S. Satpute ◽  
S. R. Wadgane ◽  
S. R. Kadam ◽  
D. R. Mane ◽  
R. H. Kadam

Abstract Y3+ substituted strontium hexaferrites having chemical composition SrYxFe12-xO19 (x= 0.0, 0.5, 1.0, 1.5) were successfully synthesized by sol-gel auto-combustion method. The structural and morphological studies of prepared samples were investigated by using X-ray diffraction technique, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy. The X-ray diffraction pattern confirmed the single-phase hexagonal structure of yttrium substituted strontium ferrite and the lattice parameters a and c increased with the substitution of Y3+ ions. The crystallite size also varied with x content from 60 to 80 nm. The morphology was studied by FE-SEM, and the grain size of nanoparticles ranged from 44 to 130 nm. The magnetic properties were investigated by using vibrating sample magnetometer. The value of saturation magnetization decreased from 49.60 to 35.40 emu/g. The dielectric constant decreased non-linearly whereas the electrical dc resistivity increased with the yttrium concentration in strontium hexaferrite.


2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
K. A. Athmaselvi ◽  
C. Kumar ◽  
M. Balasubramanian ◽  
Ishita Roy

This study evaluates the physical properties of freeze dried tropical (guava, sapota, and papaya) fruit powders. Thermal stability and weight loss were evaluated using TGA-DSC and IR, which showed pectin as the main solid constituent. LCR meter measured electrical conductivity, dielectric constant, and dielectric loss factor. Functional groups assessed by FTIR showed presence of chlorides, and O–H and N–H bonds in guava, chloride and C–H bond in papaya, and chlorides, and C=O and C–H bonds in sapota. Particle size and type of starch were evaluated by X-ray diffraction and microstructure through scanning electronic microscopy. A semicrystalline profile and average particle size of the fruit powders were evidenced by X-ray diffraction and lamellar/spherical morphologies by SEM. Presence of A-type starch was observed in all three fruits. Dependence of electric and dielectric properties on frequency and temperature was observed.


2021 ◽  
Author(s):  
Mahesh Gaidhane ◽  
Deepak Taikar ◽  
Pravin Gaidhane ◽  
Kalpana Nagde

Abstract Nanocrystalline α-Fe2O3 is synthesized by sol-gel technique. The prepared nanomaterial was characterized by X-ray diffraction (XRD), SEM, TEM, Fourier Transform Infrared (FTIR) spectroscopy, Vibrating Sample Magnetometry (VSM) and photoluminescence (PL) techniques. X-ray powder diffraction analysis confirmed the formation of α-Fe2O3. Electron microscopy showed spherical morphologies with an average particle size of 30-40 nm. The magnetic property of the prepared material was studied by VSM at room temperature. VSM study shows superparamagnetic nature of the synthesized nanoparticles. Photoluminescence (PL) emission spectra show intense broad emission band centered at 570 nm with 393 nm excitation indicating its usefulness for w-LED application. The CIE-chromaticity color coordinates of prepared material were calculated. The photocatalytic activity of the α-Fe2O3 nanoparticles was analyzed and the nanopowder exhibited good photocatalytic activity for the removal AO7 from its aqueous solution.


2017 ◽  
Vol 17 (01n02) ◽  
pp. 1760012
Author(s):  
S. Gowreesan ◽  
A. Ruban Kumar

The scope of the present work is in enhancing the particle size, and dielectric properties of Mg-substituted Cobalt ferrites nanoparticles prepared by sol–gel auto combustion method. The different ratios of Mg-substituted Co Ferrites (Co[Formula: see text]MgxFe2O4([Formula: see text], 0.05, 0.10, 0.15, 0.20 and 0.30)) are calcinated at 850[Formula: see text]C. The synthesized nanoparticles were characterized by powder XRD, FTIR, FE-SEM, EDX techniques and dielectric behavior. The structural parameters were confirmed from powder XRD and the average particle size is obtained from 39 to 67 nm due to the substitution of Mg[Formula: see text] which was calculated by Debye Scherrer’s formula. FE-SEM showed the surface morphology of the different ratio of the sample. The dielectric loss has measured the frequency range of 50[Formula: see text]Hz–5[Formula: see text]MHz. From electrical modulus, conductivity relaxation and thermal activation of charge carriers has been discussed.


2010 ◽  
Vol 177 ◽  
pp. 673-676 ◽  
Author(s):  
Jun Xue ◽  
Hou Kui Xiang ◽  
Hong Qiao Ding ◽  
Shu Li Pang ◽  
Xue Hua Wang ◽  
...  

Carbon encapsulated Fe-Cu alloys nanoparticles were synthesized by using ferric nitrate, copper nitrate as metal sources and using sucrose as carbon source. The synthesis process involved a step of hydrazine hydrate reduction in alcohol solution and a step of annealing carbonization. The as-prepared samples were characterized by X-ray diffraction technique, X-ray energy dispersion spectrograph, trans- mission electron microscopy and Raman spectroscopy. The results showed the sample was core / shell structure, the metalic core was crystalline FeCu4 alloy, the shell was amorphous carbon, and the average particle size was about 51nm. The magnetic measurement by using a vibrating sample magnetometer revealed that the sample has ultra-soft magnetic property with the saturation magnetization Ms of 13.01 emu/g, residual magnetization Mr of 0.37 emu/g and coercive forces Hc of 54.43 Oe at room temperature.


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