Microstructure and Magnetic properties of ferrite nanoparticles synthesized by  Co-precipitation method

2021 ◽  
Author(s):  
R. Sagayaraj ◽  
S.Aravazhi ◽  
G. Chandrasekaran
Keyword(s):  
Particle Size ◽  
Spinel Ferrite ◽  
Ferrite Nanoparticles ◽  
Precipitation Method ◽  
Mixed Spinel ◽  
Spinel Composition ◽  
Li Ion ◽  
Xrd Patterns ◽  
Co Precipitation ◽  
Microstructure And Magnetic Properties

Abstract In the current research, Cu0.5Co0.3Mo0.2Fe2O4 mixed ferrite nanoparticles have been synthesized using Co-precipitation method. XRD patterns show the development of polyphasic copper, cobalt and molybdenum mixed spinel composition. The particle size of ferrite system is 16nm and they are nanoparticles. The lattice constant was determined to be 8.368 Å used for the highest peak (311). FTIR spectroscopy shows the lower octahedral and higher tetrahedral frequency alignment of ions in the spinel ferrite leading to the octahedral 550 cm− 1 and the tetrahedral 471 cm− 1 vibration modes. TEM micrographs showed spherical morphology and their particle size less than 50 nm, which correlated XRD crystallite size. VSM shows excellent ferrimagnetic properties because of higher coercivity (985.29 G). These higher coercivity materials can make cathode content for Li-ion batteries.

A correlated structural and electrical study of manganese ferrite nanoparticles with variation in sintering temperature

2017 ◽  
Vol 31 (26) ◽  
pp. 1750236 ◽  
Author(s):  
Elangbam Chitra Devi ◽  
Ibetombi Soibam
Keyword(s):  
Structural Changes ◽  
Spinel Phase ◽  
Spinel Ferrite ◽  
Average Crystallite Size ◽  
Ferrite Nanoparticles ◽  
Precipitation Method ◽  
Manganese Ferrite ◽  
Absorption Bands ◽  
Metal Chlorides ◽  
Co Precipitation

Manganese ferrite nanoparticles were prepared by chemical co-precipitation method. Metal chlorides and sodium hydroxide were used as precursor. The spinel phase formation of the prepared samples was confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). From the XRD data, the average crystallite size and lattice constant were calculated. FTIR spectra reveal the characteristic absorption bands of spinel ferrite due to M-O stretching vibrations in tetrahedral and octahedral sites. Manganese ferrite nanoparticles were further given sintering. The effect of sintering at different temperatures on the structural properties such as XRD, FTIR and electrical properties such as dielectric constant, dielectric loss and ac-conductivity was studied. Possible mechanism of structural changes and observed electrical behavior due to sintering is being discussed. A strong correlation has also been observed in the results obtained from different characterization techniques.

Role of Particle Size on Structural and Magnetic Behavior of Nanocrystalline Cu-Ni Ferrite

2011 ◽  
Vol 171 ◽  
pp. 79-91 ◽  
Author(s):  
S.N. Dolia
Keyword(s):  
Particle Size ◽  
Saturation Magnetization ◽  
Fine Particles ◽  
Magnetic Moments ◽  
Magnetic Behavior ◽  
Nano Particles ◽  
Blocking Temperature ◽  
Precipitation Method ◽  
Xrd Patterns ◽  
Co Precipitation

Particle size has significant effect on the magnetic properties of fine particles. In this work, Cu0.2Ni0.8Fe2O4 nano-particles have been synthesized by the co-precipitation method. Different particle sizes were obtained by annealing the samples at various temperatures. The X-ray diffraction (XRD) patterns confirm the formation of cubic spinel structure. The particle size was found to enhance with increasing the annealing temperature. The saturation magnetization and the blocking temperature increase with particle size, which is a typical characteristic of the superparamagnetic behaviour. The dc magnetization measurements show that the samples are superparamagnetic above the blocking temperatures and the blocking temperature of the nanoparticles correlates with the size of the nanoparticles that is found to increase as the function of the particle size. The hysteresis curves show reduction in saturation magnetization in case of nanoparticles as compared to their bulk counterparts. This has been explained on the basis that the magnetic moments in the surface layers of a nanoparticle are in a state of frozen disorder. However, the saturation magnetization increases with particle size, which is a characteristic property of the single domain superparamagnetic particles.

scholarly journals Synthesis and characterization of nanocrystalline nickel - cobalt ferrites by co-precipitation Method

2015 ◽  
Vol 11 (1) ◽  
Author(s):  
Ali A. Ati ◽  
Zulkafli Othaman ◽  
Shadab Dabagh ◽  
R. M. Rosnan ◽  
Samad Zare
Keyword(s):  
Spinel Ferrite ◽  
Ftir Spectrum ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Main Metal ◽  
Nano Crystalline ◽  
Xrd Patterns ◽  
Co Precipitation

Nano crystalline powders of Co-Ni ferrite compounds having the chemical formula Co(x)Ni(1-x) Fe2O4( x = 0.0, 0.2 and 1.0) have been successfully synthesized by co-precipitation technique. These synthesized compounds are characterized by X-ray diffraction (XRD), field emission scan electron microscopy (FESEM), fourier transformed infrared (FTIR) spectrum, energy dispersive X-ray diffraction (EDX) and TGA-DTA. The XRD analyses of the samples sintered at 600 °C clearly show the formation of single cubic spinel structure. XRD patterns are further analyzed to calculate the lattice constant and jump length of charge carriers. Average crystalline sizes for ferrite powders are determined from XRD line using Debye-Scherrer's formula is found to be in the range of 16 to 19 nm with narrow size distribution. The Fourier transformed infrared (FTIR) spectrum characterization of the  spinel ferrite structure sintered at 600 °C shows two fundamental strong band in the range 385-600 cm-1, which is attributed to different main metal-oxygen bands.

Magnetic and dielectric properties study of cobalt ferrite nanoparticles synthesized by co-precipitation method

2011 ◽  
Vol 1368 ◽  
Author(s):  
M. Krishna Surendra ◽  
D. Kannan ◽  
M. S. Ramachandra Rao
Keyword(s):  
Particle Size ◽  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Saturation Magnetization ◽  
Cobalt Ferrite ◽  
Ferrite Nanoparticles ◽  
Precipitation Method ◽  
Co Precipitation ◽  
Inert Layer

Abstract:Cobalt ferrite nanoparticles were prepared by co-precipitation method and were heat treated at 100 oC, 200 oC, 400 oC and 600 oC for 2 h to increase the particle size. Phase purity of samples was confirmed by X-ray diffraction. Scherrer formula calculations showed crystallite size varied from 12 to 24 nm when heated from 100 oC to 600 oC. Transmission electron microscopy reveals a uniform and narrow particle size distribution about 12 nm for as-prepared cobalt ferrite particles. Room temperature saturation magnetization was found to vary from 40.8 to 67.0 emu/g as the particle size increased from12 nm to 24 nm. Increase in saturation magnetization with increase in particle size was attributed to the presence of magnetic inert layer on the surface of nanoparticles. Inert layer thickness calculated at 10 K and 300 K was 6 Å and 11 Å respectively. The dielectric properties ε’, tanδ, Z and θ have been studied as a function of frequency and particles size. For the 12 nm grain size, the dielectric constant is one order higher than that of bulk cobalt ferrite. Increase in the grain size showed an increase in the dielectric constant. The increase in the conductivity with grain size is mainly due to the grain size effects. The present study shows that the dielectric properties can be tailor-made to suit the requirement of a particular application by controlling the grain size.

scholarly journals Impact of Iron on the Fe–Co–Ni Ternary Nanocomposites Structural and Magnetic Features Obtained via Chemical Precipitation Followed by Reduction Process for Various Magnetically Coupled Devices Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 341
Author(s):  
Tien Hiep Nguyen ◽  
Gopalu Karunakaran ◽  
Yu.V. Konyukhov ◽  
Nguyen Van Minh ◽  
D.Yu. Karpenkov ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Reduction Process ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Magnetic Characteristics ◽  
Reduction Temperature ◽  
Fe Content ◽  
Magnetic Features ◽  
Co Precipitation

This paper presents the synthesis of Fe–Co–Ni nanocomposites by chemical precipitation, followed by a reduction process. It was found that the influence of the chemical composition and reduction temperature greatly alters the phase formation, its structures, particle size distribution, and magnetic properties of Fe–Co–Ni nanocomposites. The initial hydroxides of Fe–Co–Ni combinations were prepared by the co-precipitation method from nitrate precursors and precipitated using alkali. The reduction process was carried out by hydrogen in the temperature range of 300–500 °C under isothermal conditions. The nanocomposites had metallic and intermetallic phases with different lattice parameter values due to the increase in Fe content. In this paper, we showed that the values of the magnetic parameters of nanocomposites can be controlled in the ranges of MS = 7.6–192.5 Am2/kg, Mr = 0.4–39.7 Am2/kg, Mr/Ms = 0.02–0.32, and HcM = 4.72–60.68 kA/m by regulating the composition and reduction temperature of the Fe–Co–Ni composites. Due to the reduction process, drastic variations in the magnetic features result from the intermetallic and metallic face formation. The variation in magnetic characteristics is guided by the reduction degree, particle size growth, and crystallinity enhancement. Moreover, the reduction of the surface spins fraction of the nanocomposites under their growth induced an increase in the saturation magnetization. This is the first report where the influence of Fe content on the Fe–Co–Ni ternary system phase content and magnetic properties was evaluated. The Fe–Co–Ni ternary nanocomposites obtained by co-precipitation, followed by the hydrogen reduction led to the formation of better magnetic materials for various magnetically coupled device applications.

Microstructure Characterization of Metal Mixed Oxides

MRS Advances ◽  
2017 ◽  
Vol 2 (64) ◽  
pp. 4025-4030 ◽  
Author(s):  
T. Kryshtab ◽  
H. A. Calderon ◽  
A. Kryvko
Keyword(s):  
Mixed Oxides ◽  
Profile Analysis ◽  
Atomic Resolution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Reconstruction Procedure ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Co Precipitation

ABSTRACTThe microstructure of Ni-Mg-Al mixed oxides obtained by thermal decomposition of hydrotalcite-like compounds synthesized by a co-precipitation method has been studied by using X-ray diffraction (XRD) and atomic resolution transmission electron microscopy (TEM). XRD patterns revealed the formation of NixMg1-xO (x=0÷1), α-Al2O3 and traces of MgAl2O4 and NiAl2O4 phases. The peaks profile analysis indicated a small grain size, microdeformations and partial overlapping of peaks due to phases with different, but similar interplanar spacings. The microdeformations point out the presence of dislocations and the peaks shift associated with the presence of excess vacancies. The use of atomic resolution TEM made it possible to identify the phases, directly observe dislocations and demonstrate the vacancies excess. Atomic resolution TEM is achieved by applying an Exit Wave Reconstruction procedure with 40 low dose images taken at different defocus. The current results suggest that vacancies of metals are predominant in MgO (NiO) crystals and that vacancies of Oxygen are predominant in Al2O3 crystals.

Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder

2018 ◽  
Vol 281 ◽  
pp. 40-45
Author(s):  
Jie Guang Song ◽  
Lin Chen ◽  
Cai Liang Pang ◽  
Jia Zhang ◽  
Xian Zhong Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Hydrothermal Reaction ◽  
Synthesis Method ◽  
Particle Morphology ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Powder Materials ◽  
Co Precipitation

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

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