Preparation and Properties of CoFe2O4 Synthesized by the Modified Citrate-Gel Method

2010 ◽  
Vol 644 ◽  
pp. 39-42 ◽  
Author(s):  
E.M. Múzquiz-Ramos ◽  
Dora A. Cortés-Hernández ◽  
O.A. Herrera-Romero ◽  
José C. Escobedo-Bocardo
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Magnetic Properties ◽  
Citric Acid ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Molar Ratio ◽  
Spinel Type ◽  
Wide Range ◽  
Auto Combustion

In this work, the synthesis of CoFe2O4 via sol-gel auto-combustion method, using iron nitrate, cobalt nitrate and citric acid, with subsequent heat treatment in air was studied. The effects of the molar ratio of the metal nitrates to citric acid and the heat treatment temperatures on the magnetic properties have been investigated. The X-ray diffraction patterns showed peaks consistent with cubic spinel-type structure. The average crystallite sizes were determined from the (311) peak of the diffraction pattern using Scherrer equation. Particle sizes in the range of 18-44 nm were obtained. The crystallite size increases with annealing temperature. Magnetic properties, such as saturation magnetization (Ms), remanent magnetization (Mr) and coercivity field (Hc) were measured at room temperature using a vibrating sample magnetometer. Saturation magnetization was found to increase with particle size, whereas coercivity was found to reduce exponentially as the particle size was increased, apart from the Hc of the sample treated at 300 °C. The present work shows that magnetic properties vary over a wide range by changing the synthesis conditions.

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Rare Earth Ions ◽  
Ion Concentration ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

Structural, morphological and magnetic properties of Mn2+ ions substituted nanosized nickel–copper–cobalt ferrites through sol–gel auto-combustion method

2019 ◽  
Vol 34 (01) ◽  
pp. 2050002
Author(s):  
Wei Zhang ◽  
Aimin Sun ◽  
Xiqian Zhao ◽  
Xiaoguang Pan ◽  
Yingqiang Han
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Spinel Structure ◽  
Remanent Magnetization ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Combustion Method ◽  
Magnetic Data ◽  
Nickel Copper ◽  
Auto Combustion

Manganese substituted nickel–copper–cobalt ferrite nanoparticles having the basic composition [Formula: see text] (x = 0.0, 0.1, 0.2, 0.3 and 0.4) were synthesized by sol–gel auto-combustion method. X-ray diffraction (XRD) was used to estimate phase purity and lattice symmetry. All the prepared samples show the single-phase cubic spinel structure. Fourier transform infrared (FTIR) measurements also confirm the cubic spinel structure of the ferrite that is formed. The preparation of samples show these nearly spherical particles by Transmission electron microscopy (TEM). The magnetic properties of Mn[Formula: see text] ion substituted in nickel–copper–cobalt ferrite were studied by Vibrating sample magnetometer (VSM). The saturation magnetization ([Formula: see text]), remanent magnetization [Formula: see text], coercivity [Formula: see text], magnetic moment [Formula: see text] and anisotropy constant [Formula: see text] first increase and then decrease with the increase of [Formula: see text] ions content. They had better magnetism than pure sample and other substituted samples when the substitution amount of [Formula: see text] ions was [Formula: see text]. At [Formula: see text], the maximum values of remanent magnetization [Formula: see text], saturation magnetization [Formula: see text] and coercivity [Formula: see text] are 25.58 emu/g, 61.95 emu/g and 689.76 Oe, respectively. This indicates that the magnetism of ferrite can improve by substituting with the appropriate amount of manganese. However, due to the excess [Formula: see text] ions instead, ferrite magnetism is weakened. This means that these materials can be used in magnetic data storage and recording media.

Effects of different sintering temperature on structural and magnetic properties of Ni–Cu–Co ferrite nanoparticles

2018 ◽  
Vol 32 (27) ◽  
pp. 1850321 ◽  
Author(s):  
Xiaoguang Pan ◽  
Aimin Sun ◽  
Yingqiang Han ◽  
Wei Zhang ◽  
Xiqian Zhao
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Spinel Structure ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Stable State ◽  
Precursor Solution ◽  
Auto Combustion ◽  
Different Temperatures ◽  
Ft Ir

In this work, sol–gel auto-combustion technology is used to synthesize nanocrystalline Ni[Formula: see text]Cu[Formula: see text]Co[Formula: see text]Fe2O4 with high purity metal nitrate and citric acid as precursor solution. The prepared samples are sintered at different temperatures (400[Formula: see text]C, 500[Formula: see text]C, 600[Formula: see text]C, 700[Formula: see text]C, 800[Formula: see text]C, 900[Formula: see text]C, 1000[Formula: see text]C and 1100[Formula: see text]C) for 3.5 h. The structure and magnetic properties of the samples are characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and vibrating sample magnetometer (VSM). The analysis of the XRD patterns confirms that all the samples have a single-phase cubic spinel structure. The particle size of the prepared samples (between 23 nm and 36 nm) is determined by the Scherrer equation. The effect of particle size is through observation of samples sintered at different temperatures. FT-IR spectroscopy shows the characteristic peak is near 588 cm[Formula: see text]. And the measurement also confirms the formation of spinel structure. The magnetic parameters of the samples are measured by VSM at room temperature with a maximum magnetic field of 1 T. Coercivity, remanent magnetization and saturation magnetization change with the changing sintering temperature. It can be clearly observed that the magnetic properties increase significantly with the temperature increasing from 600[Formula: see text]C to 700[Formula: see text]C. The dM/dH versus H curves are obtained by differentiating the hysteresis loop. The increasing peak height of dM/dH at [Formula: see text], indicates a magnetically stable state for the samples with good crystalline cubic spinel structure.

scholarly journals Green Synthesis of Co-Zn Spinel Ferrite Nanoparticles: Magnetic and Intrinsic Antimicrobial Properties

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5014
Author(s):  
Alexander Omelyanchik ◽  
Kateryna Levada ◽  
Stanislav Pshenichnikov ◽  
Maryam Abdolrahim ◽  
Miran Baricic ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Chemical Composition ◽  
Saturation Magnetization ◽  
Cobalt Ferrite ◽  
Spinel Ferrite ◽  
Ferrite Nanoparticles ◽  
Ferromagnetic Behavior ◽  
Wide Range ◽  
Auto Combustion

Spinel ferrite magnetic nanoparticles have attracted considerable attention because of their high and flexible magnetic properties and biocompatibility. In this work, a set of magnetic nanoparticles of cobalt ferrite doped with zinc was synthesized via the eco-friendly sol-gel auto-combustion method. Obtained particles displayed a room-temperature ferromagnetic behavior with tuned by chemical composition values of saturation magnetization and coercivity. The maximal values of saturation magnetization ~74 Am2/kg were found in cobalt ferrite nanoparticles with a 15–35% molar fraction of cobalt replaced by zinc ions. At the same time, the coercivity exhibited a gradually diminishing trend from ~140 to ~5 mT whereas the concentration of zinc was increased from 0 to 100%. Consequently, nanoparticles produced by the proposed method possess highly adjustable magnetic properties to satisfy the requirement of a wide range of possible applications. Further prepared nanoparticles were tested with bacterial culture to display the influence of chemical composition and magnetic structure on nanoparticles-bacterial cell interaction.

Synthesis of (Ba,Ti)-Doped Apatite-Type Lanthanum Silicate Nano-Sized Powders via Microwave-Assisted Sol-Gel Auto-Combustion Route

2013 ◽  
Vol 652-654 ◽  
pp. 882-885 ◽  
Author(s):  
Ran Wu ◽  
Jia Mei Ye ◽  
Qi Zhao Li ◽  
Sheng Yun Wang ◽  
Xiu Lei Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Citric Acid ◽  
Sol Gel ◽  
Lanthanum Nitrate ◽  
Microwave Assisted ◽  
Auto Combustion ◽  
Combustion Route ◽  
Lanthanum Silicate ◽  
Apatite Type

In this paper, (Ba,Ti)-doped lanthanum silicate nano-sized powders have been synthesized via microwave assisted sol-gel auto-combustion route by using TEOS and lanthanum nitrate as the starting materials, citric acid and glycol as chelators. Both the phase compositions and morphologies of the obtained powders have been characterized. The results indicated that: the synthesized nano powders were characterized as fluffy aggregates with the particle size ranging from 50 to 100nm. As the doping contents of Ba increased, the crystalline sizes decreased and the aggregation were deteriorated, while the particle size decreased from 120nm to 80nm and the aggregation between particles were halted as the doping contents of Ti increased.

Studies on structural and magnetic properties of Ni-Mg-Co spinel ferrite nanoparticles sintered at different temperatures

2020 ◽  
Vol 34 (03) ◽  
pp. 2050041
Author(s):  
Xiqian Zhao ◽  
Aimin Sun ◽  
Wei Zhang ◽  
Lichao Yu ◽  
Zhuo Zuo ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Spinel Structure ◽  
Cobalt Ferrite ◽  
Sintering Temperature ◽  
Spinel Ferrite ◽  
Sol Gel ◽  
Peak Height ◽  
Magnetic Stability

In order to study the effect of sintering temperature on the structure and magnetic properties of nickel-magnesium-cobalt ferrite, [Formula: see text] spinel ferrite with different sintering temperatures (500[Formula: see text]C, 600[Formula: see text]C, 700[Formula: see text]C, 800[Formula: see text]C, 900[Formula: see text]C and 1000[Formula: see text]C) was prepared by sol–gel method. The magnetic properties of the prepared samples were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Vibrating sample magnetometer (VSM). The results show that the sintering temperature has a significant effect on the structure and magnetic properties of nickel-magnesium-cobalt ferrite. Analysis of the XRD pattern confirmed that all samples showed a single-phase cubic spinel structure. The particle size of the prepared sample determined by the Scherrer equation was 51 nm to 135 nm. As the sintering temperature increases from 500[Formula: see text]C to 1000[Formula: see text]C, the intensity of all peaks gradually increases, the crystallinity and particle size of the sample increase significantly, but the coercive force decreases, the saturation magnetization, the residual magnetization and the squareness [Formula: see text] increase first and then decrease. Compared with other samples, the 800[Formula: see text]C sintered samples had the highest saturation magnetization (59.03 emu/g), remanent magnetization (30.65 emu/g) and squareness (0.519). The increasing peak height of [Formula: see text] at [Formula: see text] indicates that the cubic spinel structure samples have good crystallinity and magnetic stability.

Influence of citric acid content on magnetic properties of BaFe12O19 powder prepared by sol-gel auto-combustion method

2007 ◽  
Vol 11 (3) ◽  
pp. 263-267 ◽  
Author(s):  
Min-jian Zhong ◽  
Guo-qing Xu ◽  
Hong-liang Ma ◽  
Jiong Zhou ◽  
Zhong-yue Yue ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Citric Acid ◽  
Acid Content ◽  
Sol Gel ◽  
Combustion Method ◽  
Auto Combustion ◽  
Citric Acid Content

scholarly journals Temperature Dependence of Initial Permeability of NixCo1-xFe2O4 Ferrite System

2015 ◽  
Vol 16 (4) ◽  
pp. 695-699
Author(s):  
V.S. Bushkova ◽  
A.V. Kopayev ◽  
N.I. Bushkov ◽  
B.V. Karpyk ◽  
O.M. Matkivskyi
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Surface Layer ◽  
Crystallite Size ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Initial Permeability ◽  
Nickel Cobalt ◽  
Auto Combustion ◽  
Ferrite System

The aim of this work was to create and study of ferrite nickel-cobalt powders, using sol-gel technology with participation of auto-combustion. Dependence of the initial permeability from the degree of substitution of cobalt cations on nickel cations is obtained. It is revealed that the crystallite size has a significant influence on the magnetic properties of the samples. With decreasing of crystallite size of nickel-cobalt ferrite Curie temperature decreases. It is shown that the smaller the particle size, the greater the thickness of the surface layer with significant violations of magnetic structure.

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