Effect of Reaction Time on the Coercivity of Barium Ferrite Synthesized by Hydrothermal Process

2021 ◽  
Vol 1035 ◽  
pp. 687-691
Author(s):  
Min Chen ◽  
Yin Xuan Yin ◽  
Mei Li Qi ◽  
Yong Ling Ding ◽  
Yan Min Wang
Keyword(s):  
Reaction Time ◽  
Barium Ferrite ◽  
Hydrothermal Process ◽  
Impurity Phase ◽  
Equivalent Diameter ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plane Anisotropy ◽  
Microstructure And Magnetic Properties

The barium ferrite BaFe12O19 with c-plane anisotropy, which possessed relative high saturation magnetization and low coercivity, had been synthesized by hydrothermal method with different reaction time of 5 h, 8 h,11 h,14 h, and 17 h. The X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM) were used to study the phase composition, microstructure and magnetic properties of barium ferrite, respectively. The results showed the intensities of the peak were enhanced and there was no impurity phase. With the prolonging of the reaction time to 11 h, 14 h and 17 h, the grain size increased, and the equivalent diameter was about 1 μm, and the thickness was about 100 nm. When the reaction time was 17 h，the coercivity of barium ferrite was 1104 Oe. The reduction of coercivity was ascribed to the increase of particle size and the reduction in magnetic anisotropy.

SIZE-INDUCED EFFECTS IN NANOSTRUCTURED NiFe2O4

2010 ◽  
Vol 24 (30) ◽  
pp. 5973-5985
Author(s):  
M. GUNES ◽  
H. GENCER ◽  
T. IZGI ◽  
V. S. KOLAT ◽  
S. ATALAY
Keyword(s):  
Electron Microscopy ◽  
Annealing Temperature ◽  
Structural Parameters ◽  
Hydrothermal Process ◽  
Lattice Parameter ◽  
Effect Of Temperature ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

NiFe 2 O 4 nanoparticles were successfully prepared by a hydrothermal process, and the effect of temperature on them was studied. The particles were annealed at various temperatures ranging from 413 to 1473 K. Studies were carried out using powder X-ray diffraction, scanning electron microscopy, infrared spectroscopy, differential thermal analysis, thermogravimetric analysis and a vibrating sample magnetometer. The annealing temperature had a significant effect on the magnetic and structural parameters, such as the crystallite size, lattice parameter, magnetization and coercivity.

Magnetic Ink Based on Barium Ferrite and its Application in Magnetic Recording Paper

2015 ◽  
Vol 748 ◽  
pp. 85-88 ◽  
Author(s):  
Ya Ling Li ◽  
Fu Yan Zhao ◽  
Jun Xia Zhao ◽  
Lu Hai Li
Keyword(s):  
Magnetic Recording ◽  
Barium Ferrite ◽  
Magnetic Layer ◽  
Credit Cards ◽  
Ferrite Powder ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Paper Substrate ◽  
X Ray ◽  
Identity Cards

Magnetic stripe cards and magnetic recording paper are commonly used in credit cards, identity cards, and transportation tickets. Barium ferrite was used to prepare magnetic inks and the magnetic ink was coated onto the paper substrate to obtain the magnetic papers. The crystal structure of barium ferrite was characterized by X-ray diffraction (XRD) and the magnetic property of barium ferrite was tested by vibrating sample magnetometer (VSM) The performance of the magnetic recording paper and the surface morphology of the coating magnetic layer were also characterized. The results show that the magnetic ink based on barium ferrite with the formula of 41wt% of the barium ferrite powder, 14wt% of polyurethane, 36wt% of solvent and 9wt% of PVP has good printing characteristics and the magnetic recording papers have good performance.

Preparation of Magnetite-Mg/Al Hydrotalcite through Hydrothermal Process and Subsequent Calcination

2015 ◽  
Vol 1101 ◽  
pp. 336-339 ◽  
Author(s):  
Triastuti Sulistyaningsih ◽  
Sri Juari Santosa ◽  
Dwi Siswanta ◽  
Bambang Rusdiarso
Keyword(s):  
Hydrothermal Process ◽  
Chemical Properties ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Subsequent Calcination ◽  
The Fourier Transform ◽  
Physical And Chemical ◽  
And Chemical Properties

Fe3O4/Mg-Al-NO3-hydrotalcite composite compounds have been synthesized by hydrothermal process followed by calcination to learn the differences in physical and chemical properties of each compound. Hydrothermal was performed at a temperature of 120 °C for 5 h and calcinations was at 450 °C for 3 hours. Characterization of the composite compounds was conducted using the Fourier Transform Infrared Spectroscopy (FTIR), the X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and Vibrating Sample Magnetometer (VSM). The characterization results showed that crystallinity, surface area and magnetic properties of hydrothermally treated Mg/Al hydrotalcite-magnetite were higher than those unhydrothermal and calcination products.

scholarly journals Preparation of γ-Fe2O3/Ni2O3/FeCl3(FeCl2) Composite Nanoparticles by Hydrothermal Process Useful for Ferrofluids

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Qingmei Zhang ◽  
Jian Li ◽  
Hua Miao ◽  
Jun Fu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hydrothermal Process ◽  
Composite Nanoparticles ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Amorphous Precursor ◽  
Outermost Layer ◽  
X Ray ◽  
Specific Saturation Magnetization ◽  
Transmission Electron

Using a hydrothermal process in FeCl2 solution, γ-Fe2O3/Ni2O3/FeCl3(FeCl2) composite nanoparticles were obtained from the FeOOH/Ni(OH)2 precursor prepared by coprecipitation. The precursor and the as-prepared nanoparticles were investigated by vibrating sample magnetometer (VSM), X-ray diffraction (XRD), energy disperse X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The experimental results showed that the paramagnetic amorphous precursor, in which Ni(OH)2 is formed outside FeOOH, is transformed to ferrimagnetic γ-Fe2O3/Ni2O3 composite when it is processed in FeCl2 solution (0.25, 0.50, 1.00 M) in an autoclave at 100°C for 1 hr. In addition, the dismutation reaction of FeCl2 produces FeCl3 and Fe. Some FeCl3 and little FeCl2 can be absorbed to form γ-Fe2O3/Ni2O3/FeCl3(FeCl2) composite nanoparticles in which Ni2O3 forms outside the γ-Fe2O3 core and the outermost layer is FeCl3 (FeCl2). The content of FeCl3 (FeCl2) in the particles increased, and the magnetization of the particles decreased with the concentration of FeCl2 solution increasing in the hydrothermal process. The FeCl3 (FeCl2) surface is chemically passive and nonmagnetic (paramagnetic). Accordingly, the composite nanoparticles are chemically stable, and their aggregation is prevented. The specific saturation magnetization of such composite nanoparticles can get to 57.4–62.2 emu/g and could be very suitable for synthesizing ferrofluids.

Effects of a Partial Substitution of Fe by Al on Nanostructure and Magnetic Properties of (Nd,Pr)-(Fe,Co)-B Alloys Prepared by Mechanical Alloying

2017 ◽  
Vol 48 ◽  
pp. 171-176
Author(s):  
Rahim Sabbaghizadeh ◽  
Roslinda Shamsudin ◽  
Samikanu Kanagesan ◽  
Ghazaleh Bahmanrokh
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Mechanical Alloying ◽  
Remanent Magnetization ◽  
Partial Substitution ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Microstructure And Magnetic Properties

In this study, Nanocrystalline Nd8Pr2Fe79-xCo5B6Alx (x= 0, 1, 2, 3) magnets were prepared by mechanical alloying method and respective heat treatment in a constant time and temperature. Afterward, the effects of the Al addition on the microstructure and magnetic properties of Nd-Fe-Co-B alloy were studied. The changes in the nanostructure and magnetic properties were examined by X-Ray diffraction (XRD), combined with Field Emission Scanning electron microscopy (FeSEM) and vibrating sample magnetometer (VSM). Addition of Al was found to be effective for improving the coercivity parameter and the hysteresis squareness in Nd–Fe–Co–B magnets without decreasing much the remanent magnetization.

MAGNETIC PROPERTIES AND MÖSSBAUER SPECTRA OF Fe7S8 NANORODS

2012 ◽  
Vol 11 (05) ◽  
pp. 1250036 ◽  
Author(s):  
WEIGAO WANG ◽  
FAGEN LI ◽  
FAN ZHAO ◽  
JUN WANG ◽  
GUOMENG ZHAO
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Mössbauer Spectra ◽  
Iron Sulfide ◽  
Impurity Phase ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mossbauer Spectra ◽  
Scanning Electron

Fe7S8 nanorods have been successfully synthesized using a chemical evaporation method. X-ray diffraction pattern showed that the as-prepared products were Fe7S8 with no impurity phase. The results of scanning electron microscopy indicated that the samples synthesized at 750°C and 900°C were rod and sheet-like, respectively. The magnetic properties of the iron sulfide nanorods were measured over a wide temperature range (4 K–750 K) using a quantum design vibrating sample magnetometer. It was found that the nanorods were ferromagnetic with the Curie temperature of about 581 K. The Mössbauer spectra showed that the iron sulfide nanorods consisted of hexagonal pyrrhotites, whose spectra were asymmetrical according to correlation between the isomer shift and the hyperfine field.

Preparation and Properties of Porous Barium Ferrite

2010 ◽  
Vol 177 ◽  
pp. 257-259
Author(s):  
Shu Fang Zheng ◽  
Guo Xuan Xiong ◽  
Hai Qing Huang ◽  
Liu Jun Luo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Barium Ferrite ◽  
Sol Gel ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Morphology ◽  
Gel Technique ◽  
Scanning Electron

Nano-porous Barium ferrite (BaFe12O19) nanoparticles were synthesized by sol-gel technique using CTAB as template. The structure, morphology, and magnetic properties of samples were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The results show that particles size are about 45 nm to 65 nm. And the nanoparticles show a saturation magnetization (Ms) of 62.831 emu/g, a coercivity (Hc) of 5481.0 Oe and a remament magnetization (Mr) of 33.083 emu/g.

Effect of Temperature on Fe3O4 Magnetic Nanoparticles Prepared by Coprecipitation Method

2014 ◽  
Vol 900 ◽  
pp. 172-176 ◽  
Author(s):  
Ji Mei Niu ◽  
Zhi Gang Zheng
Keyword(s):  
Magnetic Nanoparticles ◽  
Coprecipitation Method ◽  
Effect Of Temperature ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Carriers ◽  
Average Grain Size ◽  
Or Gene ◽  
Block Temperature

The Fe3O4 magnetic nanoparticles obtained by the aqueous coprecipitation method are characterized systematically using scanning electron microscope, X-ray diffraction and vibrating sample magnetometer. These magnetic nanoparticles are spheric, dispersive, and have average grain size of 50 nm. The size and magnetic properties of Fe3O4 nanoparticles can be tuned by the reaction temperature. All samples exhibit high saturation magnetization (Ms=53.4 emu·g-1) and superparamagnetic behavior with a block temperature (TB) of 215K. These properties make such Fe3O4 magnetic nanoparticles worthy candidates for the magnetic carriers of targeted-drug or gene therapy in future.

Selective oxidation of cyclopentene to glutaraldehyde by H2O2 over Nb-SBA-15

2021 ◽  
Author(s):  
yingmeng qi ◽  
Qi Han ◽  
li wu ◽  
Jun Li
Keyword(s):  
Structural Properties ◽  
Selective Oxidation ◽  
Mesoporous Materials ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
X Ray

A series of niobium-containing mesoporous materials Nb-SBA-15 have been prepared by sonication–impregnation and hydrothermal process. The dispersion and structural properties of niobium-containing species were systematically characterized by X-ray diffraction, scanning...

scholarly journals Carbon-coated magnetic particles increase tissue temperatures after laser irradiation

2015 ◽  
Vol 08 (05) ◽  
pp. 1550018 ◽  
Author(s):  
Shupeng Liu ◽  
Na Chen ◽  
Fufei Pang ◽  
Zhengyi Chen ◽  
Tingyun Wang
Keyword(s):  
Laser Irradiation ◽  
Magnetic Particles ◽  
Laser Energy ◽  
Thermal Therapy ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fbg Sensor ◽  
Transmission Electron ◽  
Carbon Coated

Purpose: This work focused on the investigation the hyperthermia performance of the carbon-coated magnetic particles (CCMPs) in laser-induced hyperthermia. Materials and methods: We prepared CCMPs using the organic carbonization method, and then characterized them with transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) spectrophotometry, vibrating sample magnetometer (VSM) and X-ray diffraction (XRD). In order to evaluate their performance in hyperthermia, the CCMPs were tested in laser-induced thermal therapy (LITT) experiments, in which we employed a fully distributed fiber Bragg grating (FBG) sensor to profile the tissue's dynamic temperature change under laser irradiation in real time. Results: The sizes of prepared CCMPs were about several micrometers, and the LITT results show that the tissue injected with the CCMPs absorbed more laser energy, and its temperature increased faster than the contrast tissue without CCMPs. Conclusions: The CCMPs may be of great help in hyperthermia applications.

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