scholarly journals Structural and magnetic studies on Co-Zn nanoferrite synthesized via sol-gel and combustion methods

2019 ◽  
Vol 37 (1) ◽  
pp. 39-54 ◽  
Author(s):  
B.B.V.S. Vara Prasad ◽  
K.V. Ramesh ◽  
A. Srinivas
Keyword(s):  
Citric Acid ◽  
Chelating Agents ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Three Samples ◽  
Crystallite Sizes ◽  
Ft Ir

AbstractCo–Zn nanocrystalline ferrites with chemical composition Co0:5Zn0:5Fe2O4 were synthesized by sol-gel and combustion methods. The sol-gel method was carried out in two ways, i.e. based on chelating agents PVA and PEG of high and low molecular weights. In auto-combustion method, the ratio of citric acid to metal nitrate was taken as 1:1, while in sol-gel method the chelating agents were taken based on oxygen balance. All the three samples were studied by thermogravimetric and differential thermal analysis for the identification of phase formation and ferritization temperature. The synthesized samples were characterized by powder X-ray diffraction and FT-IR spectroscopy without any thermal treatment. The measured lattice constants and observed characteristic IR absorption bands of the three samples are in good agreement with the reported values showing the formation of a cubic spinel structure. The crystallite sizes of all samples were determined using high intensity peaks and W-H plot. Size-Strain Plot method was also implemented since two of the samples showed low crystallite sizes. The least crystallite size (5.5 nm) was observed for the sample CZVP while the highest (23.8 nm) was observed for the sample CZCA. Cation distribution was proposed based on calculated and observed intensity ratios of selected planes from X ray diffraction data. All structural parameters were presented using experimental lattice constant and oxygen positional parameter, and they correlated with FT-IR results. Magnetic measurements were carried out using vibrating sample magnetometer at room temperature to obtain the characteristic parameters such as saturation magnetization, coercivity, remanence, squareness ratio and Bohr magnetons. Among all, the sample synthesized via citric acid autocombustion method displayed a remarkably higher magnetization of 53 emu/g and the remaining two samples displayed low magnetization values owing to their smaller crystallite sizes.

N, Fe Co-Doped TiO2 Photocatalyst Preparation by Sol-Gel Method with Visible Light Response

2013 ◽  
Vol 726-731 ◽  
pp. 673-676 ◽  
Author(s):  
Ping Yu ◽  
Shan Shan Wang ◽  
Huan Huan Li ◽  
Wen Xiu Li
Keyword(s):  
Sol Gel ◽  
Light Response ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Visible Light Response ◽  
Ft Ir ◽  
Co Doped

N, Fe co-doped TiO2 photocatalyst was synthesized by sol-gel method. The catalyst prepared was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Ultraviolet and visible spectroscopy (UV-vis). The results showed that the N, Fe co-doped TiO2 prepared had the anatase structure. The absorption edge of the photocatalyst shifted to longer wavelength and photocatalytic activity for degradation of Methylene blue (MB) under Xe-lamp (350 W) was much more active than un-doped TiO2, N-TiO2 Fe-TiO2 and P-25.

scholarly journals The effects of varying the Eu3+ concentration on the structural and optical properties of Mg1.5Al2O4.5:x% Eu3+ (0 ≤ x ≤ 2) nanophosphors prepared by sol–gel method

2018 ◽  
Vol 8 ◽  
pp. 184798041880064 ◽  
Author(s):  
VM Maphiri ◽  
BF Dejene ◽  
TE Motaung ◽  
TT Hlatshwayo ◽  
OM Ndwandwe ◽  
...  
Keyword(s):  
Single Phase ◽  
Crystal Size ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
The Eu

Mg1.5Al2O4.5: x% Eu3+ (0 ≤ x ≤ 2) nanopowders were successfully synthesized via sol–gel method. The X-ray diffraction (XRD) spectrum revealed that the Mg1.5Al2O4.5: x% Eu3+ matches the single phase of face-centred cubic MgAl2O4. The estimated average crystallite sizes calculated using the XRD spectra were found to be in the order of 4 nm. The estimated crystal size was confirmed by the high-resolution transmission electron microscopy. The energy dispersive X-ray spectroscopy confirmed the presence of all expected elementary composition (Mg, Al, O and Eu). The field emission gun scanning electron microscope showed that varying the Eu3+ concentration influence the morphology of the prepared nanophosphor. The photoluminescence results showed that the host emits the violet colour at around 382 nm, which was attributed to the defects within the band gap ( Eg) of host material. The Eu3+-doped samples showed the emission at around 560, 580, 593, 618, 655 and 704 nm which are, respectively, attributed to the 5D1 → 7F3, 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 characteristic transitions in Eu3+. The International Commission on Illumination colour chromaticity showed that the Eu3+ doping influences the emission colour.

Preparation, Characterization and Photocatalytic Preoperty of BiVO4 Photocatalyst by Sol-Gel Method

2011 ◽  
Vol 99-100 ◽  
pp. 1307-1311 ◽  
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Hai Yan Luan
Keyword(s):  
Photocatalytic Activity ◽  
Citric Acid ◽  
Sol Gel ◽  
Molar Ratio ◽  
Halogen Lamp ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Photodegradation Rate

Bismuth vanadate (BiVO4) powders were synthesized by complexing Sol-Gel method using citric acid as chelate,calcined at different temperature and characterized with X-ray diffraction (XRD), scanning electron microsoope（SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. It revealed that temperature values can influence significantly on the morphologies and structures of the products.It also found that the sample prepared with the molar ratio of citric acid to metal inons be 2:1, pH=7 and calcinated under 400°C for 5 hours was pure monoclinic BiVO4 phase.In this conditions, the sample had highest photocatalytic activity with the photodegradation rate was about 94% or so in 20min under 250W halogen lamp.

scholarly journals Synthesis, characterization and in vitro cytotoxicity study of Co and Ni ferrite nanoparticles prepared by sol-gel method

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Alexandre Pancotti ◽  
Dener Pereira Santos ◽  
Dielly Oliveira Morais ◽  
Mauro Vinícius de Barros Souza ◽  
Débora R. Lima ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Test Sample ◽  
In Vitro Cytotoxicity ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Crystallite Sizes

AbstractIn this study, we report the synthesis and characterization of NiFe2O4 and CoFe2O4 nanoparticles (NPs) which are widely used in the biomedical area. There is still limited knowledge how the properties of these materials are influenced by different chemical routes. In this work, we investigated the effect of heat treatment over cytotoxicity of cobalt and niquel ferrites NPs synthesized by sol-gel method. Then the samples were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier Transform Infrared Spectroscopy Analysis (FTIR), and X-ray fluorescence (XRF). The average crystallite sizes of the particles were found to be in the range of 20–35 nm. The hemocompatibility (erythrocytes and leukocytes) was checked. Cytotoxicity results were similar to those of the control test sample, therefore suggesting hemocompatibility of the tested materials.

Impedance Spectroscopy Study of LiTaO3 Powder Synthesized via Sol-Gel Method

2012 ◽  
Vol 545 ◽  
pp. 275-278 ◽  
Author(s):  
Lili Widarti Zainuddin ◽  
Norlida Kamarulzaman
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Impedance Spectroscopy Study

A ceramics sample of LiTaO3 was prepared using a sol-gel method. The sample is annealed at 750 °C for 48 hours. X-ray diffraction analysis indicate the formation of single phase, rhombohedral structure. An ac impedance study was used to analyse the conductivity of LiTaO3 at room temperature and at various temperatures.

Magnetic Properties of Bulk Zn0.95-XMnXFe0.05O2 Prepared by Sol-Gel Method and Subsequent Hot Pressing

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Sol Gel ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.

scholarly journals Effect of Preheating Temperature on Synthesis of Pure BiFeO3 via Sol–Gel Method

Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Pure Bifeo3 ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Preheating Temperature

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.

Effect of Synthesis Conditions on the Structure and Electrochemical Properties of LiNi1/2Mn1/2O2 by Sol Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 1447-1450
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu
Keyword(s):  
Electrochemical Properties ◽  
Sol Gel ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
Capacity Fading ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Synthesis Conditions ◽  
A Current

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.

scholarly journals The Variation Effect of Mg-doped NPs Prepared by Sol-Gel Method on its Structural Properties and Biological Activities

2021 ◽  
Vol 2114 (1) ◽  
pp. 012004
Author(s):  
Duha S. Ahmed ◽  
Noor Q. Ali ◽  
Ali A. Taha
Keyword(s):  
Biological Activities ◽  
Sol Gel ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Nio Nps ◽  
Dopant Element ◽  
Mg Doped

Abstract In this paper, we reported the synthesis of NiO NPs and Mg doped-NiO NPs using the facile sol-gel method. Besides, the influence of the variation of Mg dopant on the structural, morphological and optical properties of the prepared Mg-NiO NPs was studied. The synthesized Mg-NiO NPs nanoparticles were characterized by X-Ray Diffraction Analysis (XRD), Energy Dispersive X-ray Spectroscopy (EDS), Fourier-Transform Infrared Spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM), and UV-Vis spectrophotometer. The X-ray diffraction confirmed the formation of the cubic structure of Mg doped-NiO NPs after doping with the magnesium. The increase in the crystal size was observed with the increase in the concentration of the Mg dopant element. The FESEM images reveal the formation of nickel oxide through the appearance of spherical clusters, while the hybrids appear as wrinkled surface covered with spherical particles of magnesium. The UV-Vis spectrum showed a shift towards shorter wavelengths with an increase in the concentration of the Mg dopant element due to the quantum confinement effect. The hemolysis activity study showed that NiO NPs had a low hemolysis percentage of 1.47% and increased with increasing concentration. While, increasing of the RBC hemolysis (5.9%) after NiO doped with Mg. The antibacterial activity was studied against S. aureus and P. aeruginosa bacteria, and indicated the highest growth inhibition zones of Mg-doped NiO NPs as compared with NiO NPs against of Staphylococcus aureus and Pseudomonas aeruginosa, respectively.

Structure and Up-Conversion Luminescence Properties of Er3+-Yb3+Co-Doped TiO2 Nanocrystals Prepared by Sol-Gel Method

2009 ◽  
Vol 66 ◽  
pp. 167-170 ◽  
Author(s):  
Zhen Zhong Zhang ◽  
Ji Hong Zhang ◽  
Wei Zhou ◽  
Ming Xia Song ◽  
Wei Li ◽  
...  
Keyword(s):  
Titanium Tetrachloride ◽  
Upconversion Luminescence ◽  
Sol Gel ◽  
Green Emission ◽  
X Ray Diffraction ◽  
Red Emission ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Co Doped

Er3+/Yb3+ co-doped TiO2 nanocrystals were prepared by Sol-gel method in which titanium tetrachloride was adopted as the precursor. The structure, particle size, and optical properties of samples were characterized by X-ray diffraction(XRD), Field emission-Scanning Electron Microscopy(FE-SEM) and photoluminescence(PL) spectra. Er3+ concentration was fixed at 1.0mol%, and Yb3+ concentration was changed from 3 to 10mol%. Intense upconversion luminescence was observed when the samples were excited by 980nm laser. The dependence of upconversion luminescence on Yb3+ concentration was presented. The results show that the upconversion luminescence increases with the Yb3+ concentration and gets its peak at 5%. The ratio of red emission to green emission(R/G) was strikingly enhanced with the increase of Yb3+ concentration. Under the excitation of 980nm, the green emission in the range of 520-570nm (2H11/2, 4S3/2→4I15/2) and the red emission in the range of 640~690nm (4F9/2 →4I15/2) are both due to two photons process. The possible upconversion mechanism was discussed.

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