scholarly journals Sol-gel Autocombustion Elaboration and Physiochemical Characterizations of Cu2+ Substituted Cobalt Ferrite Nanoparticles

2020 ◽  
Vol 7 (1) ◽  
pp. 44-54
Author(s):  
N. Hamdi ◽  
L. Bessais ◽  
W. Belam
Keyword(s):  
Electrical Conductivity ◽  
Quantum Interference ◽  
Cobalt Ferrite ◽  
Magnetic Measurement ◽  
Sol Gel ◽  
Complex Impedance ◽  
Basic Structure ◽  
Host Lattice ◽  
X Ray ◽  
Substitution Procedure

Introduction: The copper doped cobalt ferrite series, with nominal formula CuXCo1-XFe2O4 (X = 0, 0.25, 0.5, 0.75, 1), has been elaborated via sol-gel autocombustion process by copper substitution procedure into cobalt ferrite framework. Methods: The five synthesized ferrites have been analyzed by X-ray powder diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy coupled to energy dispersive X-ray spectroscopy, complex impedance spectroscopy and superconducting quantum interference device magnetometry. Results and Discussion: The analysis of the results allowed to deduce that the cubic spinel basic structure was not modified by the incorporation of copper into the host lattice and the corresponding pure fine powders obtained formed by homogeneous nanoparticles. The highest electrical conductivity value, σDC(373K) = 27.03x10-3S.cm-1, was observed in the case of CuFe2O4. Conclusion: Moreover, the superparamagnetic behavior at room temperature has been confirmed by using both ZFC-FC and hysteresis magnetic measurement modes. In addition, the remarkable electrical conductivity and magnetic properties of the five explored nanoferrites, derived from the present investigation, enabled them useful in several modern nanotechnological and biomedical applications.

Ferrimagnetic Membranes for Separation of Paramagnetic and Diamagnetic Species

2002 ◽  
Vol 752 ◽  
Author(s):  
Jihye Gwak ◽  
André Ayral ◽  
Vincent Rouessac ◽  
Louis Cot ◽  
Jean-Claude Grenier ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Air Separation ◽  
Magnetic Interactions ◽  
Colloidal Solutions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Desorption

ABSTRACTFor using as separative membranes based on magnetic selectivity, nanoporous ferrimagnetic membranes of maghemite (γ-Fe2O3) and cobalt ferrite (Fe2CoO4) were prepared by the sol-gel route from ferrofluid colloidal solutions. Their magnetic properties were examined by superconductor quantum interference device (SQUID), and their structures and porous textures were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen adsorption-desorption analyses. O2-N2 adsorption and air separation experiments were carried out in order to evidence magnetic interactions in static and dynamic conditions, respectively. A small effect of an external magnetic field on the selectivity of these membranes was observed.

Effect of MCl (M = Na, K) addition on microstructure and electrical conductivity of forsterite

2020 ◽  
Vol 92 (1) ◽  
pp. 10901
Author(s):  
Saloua El Asri ◽  
Hamid Ahamdane ◽  
Lahoucine Hajji ◽  
Mohamed El Hadri ◽  
Moulay Ahmed El Idrissi Raghni ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Single Phase ◽  
Sol Gel ◽  
Complex Impedance ◽  
Transmission Spectra ◽  
Electrical Measurements ◽  
Cation Type ◽  
Edx Analyses ◽  
The Fourier Transform

Forsterite single phase powder Mg2SiO4 was synthesized by sol–gel method alongside with heat treatment, using two different cation alkaline salts MCl as mineralizers (M = Na, K) with various mass percentages (2.5, 5, 7.5, and 10 wt.%). In this work, we report on the effect of the cation type and the added amount of used mineralizer on microstructure and electrical conductivity of Mg2SiO4. The formation of forsterite started at 680–740  °C and at 630–700  °C with KCl and NaCl respectively, as shown by TG-DTA and confirmed by XRD. Furthermore, the Fourier transform infrared (FTIR) transmission spectra indicated bands corresponding to vibrations of forsterite structure. The morphology and elemental composition of sintered ceramics were examined by SEM-EDX analyses, while their densities, which were measured by Archimedes method, increased with addition of both alkaline salts. The electrical measurements were performed by Complex Impedance Spectroscopy. The results showed that electrical conductivity increased with the addition of both mineralizers, which was higher for samples prepared with NaCl than those prepared with KCl.

Study of Magnetoresistance Effect and Magnetic Properties of La0.67Sr0.33Mn1-xNixO3 (x = 0 and 0.2) Material Prepared by Sol-Gel Method

2019 ◽  
Vol 966 ◽  
pp. 363-369
Author(s):  
Utami Widyaiswari ◽  
Budhy Kurniawan ◽  
Agung Imaduddin ◽  
Isao Watanabe
Keyword(s):  
Magnetic Properties ◽  
Magnetic Measurement ◽  
Sol Gel ◽  
Mixed Valence ◽  
Magnetoresistance Effect ◽  
Metallic Behavior ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Mr Effect

Mixed valence manganite materials have been studied due to their interesting physical properties such as their magnetoresistance (MR) effect. The change of Mn3+/Mn4+ ratio affects the possible bonds between anion and cation and their spin structure that may occur in the samples. The aim of this research is to study the change of magnetoresistance effect and magnetic properties of La0.67Sr0.33MnO3 (LSMO) by doping the Mn site with Ni ion. La0.67Sr0.33Mn1-xNixO3 samples were synthesized by using sol-gel method and characterized by using X-ray diffractometer (XRD) and Energy Dispersive X-ray spectroscopy (EDX) to confirm whether Ni has been doped successfully to the parental compound or not. XRD results showed that the samples have a single phase and Ni peak has been detected in the EDX result of Ni-doped LSMO. Resistivity and magnetic measurement showed that LSMO material has ferromagnetic metallic behavior, while x = 0.20 Ni-doped LSMO sample showed paramagnetic insulator behavior. The absolute value of the MR for un-doped sample is higher than the doped sample when the low field is applied, while under the influence of the high magnetic field, it become smaller than the doped sample.

Electrochemical Performance of La0.7Sr0.3Cu1-xFexO3-δ as Cathode Material in IT-SOFCs

2010 ◽  
Vol 160-162 ◽  
pp. 666-670
Author(s):  
Min Zhang Zheng ◽  
Xiao Mei Liu
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Cathode Material ◽  
Single Phase ◽  
Cathodic Polarization ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cathodic Overpotential ◽  
A Current

To obtain more detail information about the cathode of La0.7Sr0.3Cu1-xFexO3-δ（x= 0.1,0.3,0.5,0.7,0.9）in IT-SOFCs, the cathode material La0.7Sr0.3Cu1-xFexO3-δ（x=0.1, 0.3, 0.5, 0.7, 0.9）was synthesized by a sol-gel method. X-ray diffraction revealed it to be form a single phase of perovskite. The high temperature electrical conductivity was measured by using the four-point dc technique, and cathodic overpotential with SDC（Sm0.15Ce0.85O1.925） electrolyte support was measured by using a current-interruption technique. The investigation of electrocheimical properties suggested that La0.7Sr0.3Cu0.7Fe0.3O3-δ has the highest electrical conductivity and the lowest cathodic polarization. Using La0.7Sr0.3Cu0.7Fe0.3O3-δ as cathode and 65%NiO/SDC as anode based on SDC electrolyte one can obtain higher current density and power density at intermediate temperatures, La0.7Sr0.3Cu0.7Fe0.3O3-δ is considered to be a possible cathode adapted to IT-SOFCs.

Sol–gel synthesis, structural and electrical properties of Li2CoSiO4 cathode material

2014 ◽  
Vol 07 (06) ◽  
pp. 1440001 ◽  
Author(s):  
Michał Świętosławski ◽  
Marcin Molenda ◽  
Piotr Natkański ◽  
Piotr Kuśtrowski ◽  
Roman Dziembaj ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Sol Gel ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structural And Electrical Properties ◽  
Potential Alternative ◽  
Sol Gel Synthesis ◽  
First Time

Polyanionic cathode materials for lithium-ion batteries start to be considered as potential alternative for layered oxide materials. Among them, Li 2 CoSiO 4, characterized by outstanding capacity and working voltage, seems to be an interesting substitute for LiFePO 4 and related systems. In this work, structural and electrical investigations of Li 2 CoSiO 4 obtained by sol–gel synthesis were presented. Thermal decomposition of gel precursor was studied using EGA (FTIR)-TGA method. Chemical composition of the obtained material was confirmed using X-ray diffraction and energy-dispersive X-ray spectroscopy. The morphology of β- Li 2 CoSiO 4 was studied using transmission electron microscopy. High temperature electrical conductivity of Li 2 CoSiO 4 was measured for the first time. Activation energies of the electrical conductivity of two Li 2 CoSiO 4 polymorphs (β and γ) were determined. The room temperature electrical conductivity of those materials was estimated as well.

Sol–gel synthesis, X-ray photoelectron spectroscopy and electrical conductivity of Co-doped (La, Sr)(Ga, Mg)O3−δ perovskites

2007 ◽  
Vol 27 (13-15) ◽  
pp. 4291-4296 ◽  
Author(s):  
Riccardo Polini ◽  
Alessia Falsetti ◽  
Enrico Traversa ◽  
Oliver Schäf ◽  
Philippe Knauth
Keyword(s):  
Electrical Conductivity ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
X Ray ◽  
Sol Gel Synthesis ◽  
Co Doped

Photoluminescence Characteristics of Sol–Gel Derived ZnTiO3 Doped with Ni2+ Ion

2013 ◽  
Vol 544 ◽  
pp. 360-363 ◽  
Author(s):  
You Hua Yu ◽  
Meng Xia ◽  
Li Li Liu ◽  
Wei Jie Wu
Keyword(s):  
Sol Gel ◽  
Luminescent Properties ◽  
Host Lattice ◽  
Deionized Water ◽  
Luminescence Spectra ◽  
X Ray Diffraction ◽  
Spectra Analysis ◽  
X Ray ◽  
Water As Solvent ◽  
Sol Gel Process

ZnTiO3 doped with Ni 2+ ion has been prepared at a relatively low temperature of 600°C from the precursor derived from sol-gel process using deionized water as solvent. X-ray diffraction analysis indicates that the doped samples exhibit a hexagonal ZnTiO3 structure. From the luminescence spectra analysis, the introduction of Ni2+ ions into ZnTiO3 results in novel luminescent properties. And the relative intensity of the bands varies with the concentration of Ni2+ ions. It is demonstrated that the Ni2+ ion has taken the place of Zn2+ ion in the host lattice of ZnTiO3.

Synthesis and Characterization of Cobalt Ferrite Nanoparticles via Sol-Gel Auto Combustion Method

2020 ◽  
Vol 307 ◽  
pp. 58-63
Author(s):  
Che Zaheerah Najeehah ◽  
Kashif Tufail Chaudhary ◽  
Jalil Ali
Keyword(s):  
Crystallite Size ◽  
Spinel Structure ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Combustion Method ◽  
Spectral Lines ◽  
Hysteresis Curve ◽  
X Ray ◽  
Tauc Plot ◽  
Auto Combustion

This article reports the synthesis of cobalt ferrite (CoFe2O4) nanoparticles by low-cost sol-gel auto combustion method. The synthesized CoFe2O4 nanoparticles were characterized using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray (EDX), UV-Visible (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR) and Vibrating Sample Magnetometry (VSM). The XRD pattern inferred the formation of cubic spinel structure with average crystallite size 35.3 nm. The crystallite size was obtained in the range 32-37.5 nm in FESEM analysis. The elemental composition was confirmed using EDX spectroscopy. The presence of spectral lines at positions 465.57 cm-1 and 577.52 cm-1 associated to stretching vibrations of Co-O in octahedral sites and Fe-O in tetrahedral sites confirmed the spinel structure. The magnetic properties such as saturation magnetization (Ms) 67.79 emu/g, coercivity (Oe) 874.76 Oe and remnant (Mr) 29.07 emu/g were obtained from the hysteresis curve. The bandgap 1.409 eV was obtained for synthesized CoFe2O4 using Tauc plot from UV-Vis absorption spectra.

scholarly journals Magnetic and dielectric properties of Ca-substituted BiFeO3 nanoferrites by the sol-gel method

2018 ◽  
Vol 16 (1_suppl) ◽  
pp. 93-100 ◽  
Author(s):  
Jinpei Lin ◽  
Zeping Guo ◽  
Mei Li ◽  
Qing Lin ◽  
Kangling Huang ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Sol Gel ◽  
Diffraction Peak ◽  
Multiferroic Material ◽  
Superconducting Quantum Interference Device ◽  
X Ray ◽  
Calcination Temperatures ◽  
Main Diffraction Peak ◽  
Microwave Network Analysis

Background: A multiferroic material can simultaneously show two or more basic magnetic properties, including ferromagnetism, antiferromagnetism, and ferroelectricity. BiFeO3 is a multiferroic material with a rhombohedral distorted perovskite structure. Doping can reduce the volatility of Bi and greatly improve the magnetoelectric properties of BiFeO3. Methods: To investigate the influence of the doping content we used the following analytical methods: X-ray powder diffraction (XRD), scanning electron microscopy (SEM), microwave network analysis (PNA-N5244A), and the Superconducting Quantum Interference Device (Quantum Design MPMS) test. Results: With the increase of Ca2+ concentration in the solution, the grain size of Bi1- xCa xFeO3 becomes smaller, showing the role of Ca2+ ions as the dopant for fine grains. The calcination temperatures are the major causes for the saturated magnetization. The residual magnetization ( Mr) and the coercive force ( Hc) decrease linearly with the increase of x value, and due to the effect of Ca2+ substitution at Bi3+ sites, which causes the valence change of Fe and/or the oxygen vacancies. Conclusions: The XRD result indicates that the diffraction peak emerges with the increase of Ca2+ and the main diffraction peak achieves a high angle. The best calcining temperature is 600 °C, and the morphology is very dependent on the calcining temperature.

scholarly journals Phase Pure Synthesis and Morphology Dependent Magnetization in Mn Doped ZnO Nanostructures

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Murtaza Saleem ◽  
Shahid Atiq ◽  
Shahid M. Ramay ◽  
Asif Mahmood ◽  
Saadat A. Siddiqi ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Magnetic Measurements ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Electron Microscopic ◽  
Structural Morphology ◽  
X Ray ◽  
Phase Pure ◽  
Doped Zno ◽  
Mn Doped

Zn0.95Mn0.05O nanostructures were synthesized using sol gel derived autocombustion technique. As-burnt samples were thermally annealed at different temperatures (400, 600, and 800°C) for 8 hours to investigate their effect on structural morphology and magnetic behavior. X-ray diffraction and scanning electron microscopic studies demonstrated the improvement in crystallinity of phase pure wurtzite structure of Mn doped ZnO with variation of annealing temperature. Energy dispersive X-ray elemental compositional analysis confirmed the exact nominal compositions of the reactants. Electrical resistivity measurements were performed with variation in temperature, which depicted the semiconducting nature similar to parent ZnO after 5 at% Mn doping. Magnetic measurements by superconducting quantum interference device detected an enhanced trend of ferromagnetic interactions in thermally annealed compositions attributed to the improved structural morphology and crystalline refinement process.

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