scholarly journals Changing the Magnetic Properties of Cobalt Ferrite Nanoparticles with Different Fabrication Conditions

2021 ◽  
Vol 37 (2) ◽  
Author(s):  
Nguyen Ngoc Huyen ◽  
Nguyen Thi Minh Hong ◽  
Pham Duc Thang ◽  
Tran Dang Thanh ◽  
Ho Thi Anh
Keyword(s):  
Magnetic Properties ◽  
Spinel Structure ◽  
Cobalt Ferrite ◽  
Magnetic Hysteresis ◽  
Average Diameter ◽  
Xrd Analysis ◽  
Degree Of Crystallinity ◽  
Nanocrystalline Powders ◽  
Hydrothermal Route ◽  
Synthesis Conditions

In this study, crystalline nanoparticles CoFe2O4 with a spinel structure were prepared by hydrothermal methods. The magnetic properties of non-calcined cobalt ferrite formed from nanocrystalline powders. The dependence of the particle size and crystalline structure of obtained nanoparticles in the synthesis conditions was examined and characterized using field emission scanning electron microscope (FESEM), and X-ray diffraction analysis (XRD). The XRD analysis revealed a high degree of crystallinity and confirmed the spinel structure of crystalline nanoparticles CoFe2O4. The FESEM image shows the presence of spherical ferrite particles with an average diameter of about 13-18 nm. The results also show that the formation of cobalt ferrite spinel structures was affected by fabrication conditions. Magnetic hysteresis loop data confirm that the magnetic properties of nanoparticles depend on the synthesis conditions. The material prepared by the hydrothermal route and calcination at 150ºC with molar ration Co2+: Fe3+ = 1:2.2  for 2 hours has higher magnetic saturation than that of the surveyed samples.

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.

Magnetic Properties of Irradiated Nickel Ferrite Thermoplastic Natural Rubber Nanocomposite

2014 ◽  
Vol 879 ◽  
pp. 206-212 ◽  
Author(s):  
Sivanesan Appadu ◽  
Sahrim Hj. Ahmad ◽  
Chantara Thevy Ratnam ◽  
Meor Yahaya Razali ◽  
Moayad Husein Flaifel ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Thermal Properties ◽  
Natural Rubber ◽  
Weight Ratio ◽  
Xrd Analysis ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Magnetic Microstructure ◽  
Sem Image ◽  
Thermoplastic Natural Rubber

The effect of electron beam (EB) irradiation at different doses on the magnetic, microstructure, morphological and thermal properties of NiFe2O4/Thermoplastic Natural Rubber (TPNR) nanocomposite was investigated. The NiFe2O4/TPNR nanocomposite samples were prepared by using a Haake mixer in weight ratio of 12:88. The TPNR matrix consists of natural rubber (NR), liquid natural rubber (LNR) and high density polyethylene (HDPE) in weight ratio of 20:10:70. The samples were irradiated using a 2 MeV EB machine in doses from 0 - 200 kGy. Magnetic properties studied by using the vibrating sample magnetometer (VSM) at room temperature showed that the values of saturation magnetization (MS), remanence magnetization (MR) and the coercivity (HC) value increased with increasing doses of irradiation. The increase in MSand MRvalues is attributed to the increase in concentration of Fe3+ions at octahedral B-site and decrease of concentration at the tetrahedral A-site in the NiFe2O4cubic structure. X-ray diffraction (XRD) analysis of the samples showed that peak intensities decreased and the width of the peaks increased with increasing doses of irradiation. Scanning electron microscope (SEM) image of the nanocomposite cross section showed the presence of defects which is more visible with increasing doses of irradiation. In the case of thermal properties, differential scanning calorimetry (DSC) analysis showed that the crystallization temperature (Tc) and the degree of crystallinity (Xc) of the nanocomposite samples decreased with increasing doses of irradiation due to crosslinking of polymeric chains which hinders the growth of crystals.

Investigation of Structural, Electrical and Magnetic Properties of Mixed Ferrite System

2014 ◽  
Vol 1047 ◽  
pp. 119-122
Author(s):  
Nidhi M. Astik ◽  
G.J. Baldha
Keyword(s):  
Magnetic Properties ◽  
Spinel Structure ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Stoichiometric Mixture ◽  
Ceramic Method ◽  
Oxygen Ions ◽  
Electrical And Magnetic Properties ◽  
Metallic Cations ◽  
Polycrystalline Form

The mineral having chemical compositional formula MgAl2O4 is called “spinel”. The ferrites crystallize in spinel structure are known as spinel-ferrites or ferro-spinels. The spinel structure has an fcc cage of oxygen ions and the metallic cations are distributed among tetrahedral (A) and octahedral (B) interstitial voids (sites). A compound of Co0.85Ca0.15-yMgyFe2O4 (y=0.05, 0.10, 0.15) is synthesized in polycrystalline form, using the stoichiometric mixture of oxides with conventional standard ceramic technique and characterized by X-ray diffraction (XRD).The XRD analysis confirmed the presence of cubic structure. The intensity of each Bragg plane is sensitive to the distribution of cations in the interstitial voids of the spinel lattice. The computer program Powder X software for XRD analysis has been utilized for this purpose. The compositions of Co0.85Ca0.15-yMgyFe2O4 (y=0.05, 0.10, 0.15) ferrites have been prepared by standard ceramic method with double sintering at 950°C, 1100°C. In present study, we report the structural, electrical and magnetic properties of above said compound.

Dielectric and Magnetic Properties of Sintered Cobalt Ferrite Derived from Nanocrystalline Powders

2012 ◽  
Vol 476-478 ◽  
pp. 726-729 ◽  
Author(s):  
Liang Neng Wu ◽  
Li Zhen Jiang ◽  
Fang Yu Hong
Keyword(s):  
Dielectric Constant ◽  
Magnetic Properties ◽  
Hysteresis Loop ◽  
Loss Tangent ◽  
Room Temperature ◽  
Cobalt Ferrite ◽  
Relative Dielectric Constant ◽  
Nanocrystalline Powders ◽  
Magnetic Characteristics ◽  
Dielectric Constant And Loss

A kind of Cobalt ferrite ceramics were successfully prepared by using nanocrystalline powders synthesized by citrate gel method. The relative dielectric constant and loss tangent of the ceramic as a function of frequency (100 Hz - 1 MHz) was investigated at room temperature. Both of them decrease with increase in frequency showing dispersion. Hysteresis loop magnetization was measured and the ceramic show good magnetic characteristics at room temperature.

Structural and Magnetic Properties of CoFe2O4 / Si (001) Thin Films via Sol-Gel Method

2013 ◽  
Vol 744 ◽  
pp. 315-318
Author(s):  
Wei Rao ◽  
Ding Guo Li ◽  
Hong Chun Yan
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Exchange Coupling ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Magnetic Hysteresis ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcined Temperature

Cobalt ferrite (CoFe2O4) thin films have been prepared on Si (001) substrates, with different calcined temperatures (Tcal=400°C~800°C). The films structure was studied by X-ray diffraction (XRD) and their surface was examined by scanning electron microscopy (SEM). The magnetic properties were measured with a vibrating sample magnetometer (VSM). For low calcined temperatures, the films presented a mixture of a CoFe2O4phase, with the cubic spinel structure, and cobalt and iron antiferromagnet oxides with CoO and FeO stoichiometries. As the calcined temperature increased, the CoO and FeO relative content strongly decreased, so that for Tcal=800°Cthe films were composed mainly by polycrystalline CoFe2O4. The magnetic hysteresis cycles measured in the films were horizontally shifted due to an exchange coupling field originated by the presence of the antiferromagnetic phases.

scholarly journals Studying the influence of synthesis parameters on the magnetic properties of CoNe ferrites

2020 ◽  
Vol 3 (2) ◽  
pp. 33-38
Author(s):  
L. A. Frolova ◽  
◽  
T. Ye. Butyrina ◽  
Keyword(s):  
Magnetic Properties ◽  
Coercive Force ◽  
Magnetic Hysteresis ◽  
Reaction Medium ◽  
Nonequilibrium Plasma ◽  
Treatment Temperature ◽  
Synthesis Conditions ◽  
Synthesis Parameters ◽  
Initial Ph ◽  
Mathematical Equations

The influence of synthesis conditions on saturation magnetization and coercive force of NiCo ferrites, which were obtained under the action of low-temperature contact nonequilibrium plasma (PNP), is investigated. The main influencing factors were the initial pH of the solution, the treatment temperature and the duration of plasma treatment. Mathematical equations adequately describe the obtained dependences. The results showed that the pH of the reaction medium is the parameter that most affects the magnetic hysteresis for samples obtained by processing KNP. Increasing the initial pH leads to an increase in coercive force.

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.

Structural, morphological and magnetic properties of Ni–Cu–Co ferrites by the Sm3+ ions substitution

2020 ◽  
Vol 34 (23) ◽  
pp. 2050236
Author(s):  
Lichao Yu ◽  
Aimin Sun ◽  
Nanzhaxi Suo ◽  
Zhuo Zuo ◽  
Xiqian Zhao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Spinel Structure ◽  
Morphological Changes ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Doping Amount ◽  
X Ray ◽  
Magnetic Parameters ◽  
Crystallite Sizes

In this experiment, samarium ion was doping into nickel–copper–cobalt ferrite system by sol–gel self-propagation. The prepared chemical formula is [Formula: see text]-[Formula: see text] ([Formula: see text], 0.025, 0.05, 0.075 and 0.1). The X-ray diffraction (XRD) analysis of the samples confirms the formation of a cubic spinel structure. The average crystallite sizes are about 66–88 nm for all the prepared samples. Fourier transform infrared spectroscopy (FTIR) measurements showed all the prepared samples had Fe–O absorption peaks. This finding further confirms that the prepared sample has a spinel structure. The morphological changes of the samples were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). According to the characterization results, the surface morphology shows spherical grains. Energy-dispersive X-ray spectroscopy (EDX) test results showed that the as-prepared pure samples contained Ni, Cu, Co, Fe elements, whereas other samples contained Sm elements and the contents were different. This indicates that the prepared samples are purer and the doping amount has been increased. The magnetic parameters of samples were measured by vibration sample magnetometer (VSM) at room temperature. The analysis of magnetic parameters shows that the saturation magnetization [Formula: see text] and remanent magnetization [Formula: see text] of the sample decrease with the increase of the doping amount of samarium ions. From the magnetic parameters, it can be concluded that [Formula: see text]-doped Ni–Cu–Co ferrites have low magnetic properties.

scholarly journals CoFe2O4 Nanomaterials: Effect of Annealing Temperature on Characterization, Magnetic, Photocatalytic, and Photo-Fenton Properties

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 885 ◽  
Author(s):  
Nguyen Thi To Loan ◽  
Nguyen Thi Hien Lan ◽  
Nguyen Thi Thuy Hang ◽  
Nguyen Quang Hai ◽  
Duong Thi Tu Anh ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Photocatalytic Activity ◽  
Rhodamine B ◽  
Cobalt Ferrite ◽  
Annealing Temperature ◽  
Xrd Analysis ◽  
Band Gap Energy ◽  
Cofe2o4 Nanoparticles ◽  
X Ray ◽  
Cobalt Ferrites

In this research, structural, magnetic properties and photocatalytic activity of cobalt ferrite spinel (CoFe2O4) nanoparticles were studied. The samples were characterized by X-ray powder diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), transmission electronic microscopy (TEM), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR), and UV-visible diffused reflectance spectroscopy (DRS) analysis. The XRD analysis revealed the formation of the single-phase CoFe2O4 with a cubic structure that is annealed at 500–700 °C in 3 h. The optical band gap energy for CoFe2O4 was determined to be in the range of 1.57–2.03 eV. The effect on the magnetic properties of cobalt ferrites was analyzed by using a vibrating sample magnetometer (VSM). The particle size and the saturation magnetization of cobalt ferrite nanoparticles increased with increasing annealing temperature. The photocatalytic activity of CoFe2O4 nanoparticles was investigated by using rhodamine B dye under visible light. The decomposition of rhodamine B reached 90.6% after 270 min lighting with the presence of H2O2 and CF500 sample.

Synthesis of Cobalt Ferrite Particles by Utilized Sol-Gel Method

2015 ◽  
Vol 827 ◽  
pp. 219-222 ◽  
Author(s):  
Togar Saragi ◽  
Siti Nurjannah ◽  
Ricca Novia ◽  
Norman Syakir ◽  
Edward Simanjuntak ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spinel Structure ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
High Quality ◽  
Xrd Pattern ◽  
Gel Method ◽  
Sol Gel Method ◽  
Temperature Solution

Cobalt ferrite (CoFe2O4) nanoparticles were successfully synthesized by utilized sol gel method with controlled pH and temperature solution during reflux process in order to obtain monodispersed nanoparticles with high magnetic properties. The obtained cobalt ferrite particles are oval with the size vary from 100 nm to 220 nm. The Co˗O and Fe˗O bonds are formed as confirmed by FTIR measurement. The sample has high quality crystal with spinel structure as indicated by similar XRD pattern of the sample and the JCPDS (00-001-1121) data without impurity peaks. From the Vibrating Sample Magnetometer (VSM) measurement, magnetic remnant around 0.2303 emu/cc and coercive field around 2.7039 kOe are obtained.

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