Investigation on Phase Evolution in the Processing of Nano-Crystalline Cobalt Ferrite by Solid-State Reaction Route

2013 ◽  
Vol 829 ◽  
pp. 767-771 ◽  
Author(s):  
Hamid Akbari Moayyer ◽  
Abolghasem Ataie
Keyword(s):  
Iron Oxide ◽  
Cobalt Ferrite ◽  
Magnetic Behavior ◽  
Phase Evolution ◽  
Molar Ratio ◽  
Nanocrystalline Powder ◽  
Oxide Ceramic ◽  
X Ray Diffraction ◽  
Nano Crystalline ◽  
Structure Morphology

Cobalt ferrite nanocrystalline powder was synthesized from the powder mixture of cobalt carbonate and iron oxide by mixed oxide ceramic method. The effects of temperature of calcination as well as molar ratio of CoCO3/Fe2O3on the phase structure, morphology and magnetic properties of the products were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM) techniques, respectively. The samples calcined at 800 and 900 C consisted of cobalt ferrite, iron oxide and cobalt oxide. In the sample calcined at 1000 C, the reaction was completed and single phase CoFe2O4with a mean crystallite and particle sizes of 49 and 300 nm, respectively was obtained. The above sample showed hard magnetic behavior with a coercivity of 337 Oe, saturation magnetization of 76 emu/g and remanence of 19 emu/g.

Synthesis and Effect of Some Parameters through Reverse Micelles Route of Iron Oxide Nanoparticles

2009 ◽  
Vol 152-153 ◽  
pp. 205-208 ◽  
Author(s):  
H. Arabi ◽  
S. Nateghi ◽  
S. Sadeghi
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Reverse Micelles ◽  
Room Temperature ◽  
Molar Ratio ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Significant Difference ◽  
Vibration Sample Magnetometer

Iron oxide nanoparticles were synthesis by reverse micelle method. X-ray diffraction technique and vibration sample magnetometer were applied to characterize the produced samples at different conditions and parameters for synthesis route. There is no significant difference between samples prepared at 5°C and room temperature except a better crystalline at room temperature. The molar ratio of water to surfactant (w parameter) and concentration of the salt solution on size and magnetic properties of nanoparticles have been investigated. Increasing w leads to producing particles with larger size i.e. for w=16.83, 11.22, and 5.6, particles size are 15.22, 11.66 and 10.5 nm, respectively. The size of nanoparticles are in the range of 9 to 20 nanometers

Synthesis, thermal and magnetic behavior of iron oxide-polymer nanocomposites

2018 ◽  
Vol 25 (1) ◽  
pp. 189-195 ◽  
Author(s):  
A. Suhasini ◽  
K.P. Vinod Kumar ◽  
T. Maiyalagan
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Polymer Nanocomposites ◽  
Magnetic Behavior ◽  
Mechanical Analysis ◽  
X Ray Diffraction ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Transmission Electron ◽  
Uniform Dispersion ◽  
Spectroscopy Studies

AbstractPolymer nanocomposites of various concentrations were prepared using iron oxide (Fe2O3) nanoparticles as filler in an 80:20 ratio of the polyurethane diol and polycaprolactone hybrid. Fourier transformed infrared spectroscopy studies were performed to find out the interaction of the nanoparticles with the polymer blend. Fe2O3in the polymer composites was in the nanoscale and uniform dispersion was achieved, as revealed by X-ray diffraction. The thermal stability of the blend was assessed through thermogravimetry analysis and dynamic mechanical analysis. High-resolution scanning electron microscopy and transmission electron microscopy images ensured the development of the polymer hybrid around Fe2O3nanoparticles and the prepared composites were indeed in the nanoscale. The magnetic behavior of the prepared nanocomposites is superparamagnetic with high magnetization values, as assessed by vibrating sample magnetometry analysis.

scholarly journals Superparamagnetic Iron Oxide (Fe3O4) Nanoparticles Coated with PEG/PEI for Biomedical Applications: A Facile and Scalable Preparation Route Based on the Cathodic Electrochemical Deposition Method

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Isa Karimzadeh ◽  
Mustafa Aghazadeh ◽  
Taher Doroudi ◽  
Mohammad Reza Ganjali ◽  
Peir Hossein Kolivand
Keyword(s):  
Iron Oxide ◽  
Electrochemical Deposition ◽  
Biomedical Applications ◽  
Superparamagnetic Iron Oxide ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Deposition Method ◽  
Preparation Route ◽  
Magnetite Phase

Cathodic electrochemical deposition (CED) is introduced as an efficient and effective method for synthesis and surface coating of superparamagnetic iron oxide nanoparticles (SPIONs). In this way, bare Fe3O4 nanoparticles were electrosynthesized through CED method from aqueous solution Fe3+ : Fe2+ chloride (molar ratio of 2 : 1). In the next step, the surface of NPs was coated with polyethyleneimine (PEI) and polyethylene glycol (PEG) during the CED procedure, and PEG/PEI coated SPIONs were obtained. The prepared NPs were evaluated by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), and field-emission scanning electron microscopy (FE-SEM). The pure magnetite phase and nanosize (about 15 nm) of the prepared NPs were confirmed by XRD and FE-SEM. The presence of two coats (i.e., PEG and PEI) on the surface of electrosynthesized NPs was proved via FTIR results. The percentage of polymer coat (37.5%) on the NPs surface was provided by TGA analysis. The high magnetization value, negligible coercivity, and remanence measured by VSM indicate the superparamagnetic nature of both prepared NPs. The obtained results confirmed that the prepared Fe3O4 nanoparticles have suitable physicochemical and magnetic properties for biomedical applications.

Combustion Synthesis of Nanocrystalline Y2O2S: Eu 3+ , Mg 2+ , Ti 4+ Red Long-Lasting Phosphors Using Mixture Fuel of Thiourea and Citric Acid

2013 ◽  
Vol 652-654 ◽  
pp. 669-672 ◽  
Author(s):  
Xiao Bao Han ◽  
Xiang Guo Li ◽  
Gui Hua Peng ◽  
Zhen Hua Liang ◽  
Xia Wang
Keyword(s):  
Citric Acid ◽  
Luminescent Properties ◽  
Combustion Method ◽  
Molar Ratio ◽  
Hexagonal Crystal Structure ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
Red Emission ◽  
X Ray ◽  
Structure Morphology

Nanocrystalline Y2O2S: Eu3+, Mg2+, Ti4+red long-lasting phosphor was synthesized successfully by combustion method using thiourea and citric acid as fuel. The structure, morphology and luminescent properties of these phosphors were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectroscopy (PL). The experimental results revealed that the phosphor was composed of sheet-shaped Y2O2S with hexagonal crystal structure. They exhibited strong red emission at 617 nm and 626nm. In addition, the dosage of citric acid has great effect on the phosphor. When molar ratio of citric acid to Y3+is 1.3, the resulted phosphor gives the highest emission intensity.

scholarly journals Morphology and Photoluminescence of Ba0.5Sr0.5MoO4Powders by a Molten Salt Method

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ling Wei ◽  
Yunfei Liu ◽  
Yinong Lu ◽  
Tao Wu
Keyword(s):  
Molten Salt ◽  
Great Influence ◽  
Emission Peak ◽  
Molar Ratio ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
Soaking Time ◽  
X Ray ◽  
Structure Morphology ◽  
Phase Size

Ba0.5Sr0.5MoO4powders with scheelite-type tetragonal structure were successfully synthesized by a molten salt method. The structure, morphology, and luminescent property of the as-prepared powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL), respectively. The results show that the tetragonal Ba0.5Sr0.5MoO4powders were synthesized at 650°C for 6 h by the molten salt method. The calcining temperature, the soaking time, and the molar ratio of the salt to Na2MoO4have great influence on the phase, size, morphology, and PL properties. The better crystallinity and smaller particle size, the higher PL emission peak is.

scholarly journals Nanostructure-Related Magnetic Properties of Various Mesoporous Cobalt Oxide and Cobalt Ferrite Spinel Phases

2019 ◽  
Author(s):  
Roberto Köferstein
Keyword(s):  
Magnetic Properties ◽  
Cobalt Oxide ◽  
Cobalt Ferrite ◽  
Magnetic Ordering ◽  
Magnetic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spinel Phases ◽  
Ferrite Spinel

Nanostructure-related magnetic properties are investigated systematically for various mesoporous cobalt oxide (Co3O4) and cobalt ferrite (CoFe2O4) spinel phases. Synthesis of thematerials by nanocasting offers the opportunity to obtain materials which are different from each other with respect to both specific surface area and crystallite size. As a result, the respective contributions of two types of interfaces, namely, “solid–gas” and “solid–solid” interfaces, to the magnetic ordering can be distinguished. Structural characterization of the porous materials by X-ray diffraction, N2 physisorption, and electron microscopy as well as investigation of the magnetic behavior (field-dependent magnetization and temperaturedependentsusceptibility) are presented.

scholarly journals Effects of Al3+ Substitution on Structural and Magnetic Behavior of CoFe2O4 Ferrite Nanomaterials

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 750 ◽  
Author(s):  
Qing Lin ◽  
Yun He ◽  
Jianmei Xu ◽  
Jinpei Lin ◽  
Zeping Guo ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Cobalt Ferrite ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Ion Concentration ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Superparamagnetic Behavior ◽  
X Ray

A sol-gel autocombustion method was used to synthesize Al3+ ion-substituted cobalt ferrite CoAlxFe2−xO4 (x = 0–1.5). According to X-ray diffraction analysis (XRD), cobalt ferrite was in a single cubic phase after being calcined at 1000 °C for 3 h. Moreover, the lattice constant decreased with increase in aluminum substituents. When the sample was analyzed by Scanning Electron Microscopy (SEM), we found that uniformly sized, well-crystallized grains were distributed in the sample. Furthermore, we confirmed that Al3+ ion-substituted cobalt ferrite underwent a transition from ferrimagnetic to superparamagnetic behavior; the superparamagnetic behavior was completely correlated with the increase in Al3+ ion concentration at room temperature. All these findings were observed in Mössbauer spectra. For the cobalt ferrite CoAlxFe2−xO4, the coercivity and saturation magnetization decrease with an increase in aluminum content. When the annealing temperature of CoAl0.1Fe1.9O4 was steadily increased, the coercivity and saturation magnetization initially increased and then decreased.

scholarly journals Synthesis and Characterization of Cobalt Ferrite through Co-Precipitation Technique

2020 ◽  
Vol 10 (1) ◽  
pp. 1871-1876
Keyword(s):  
Cobalt Ferrite ◽  
Magnetic Behavior ◽  
Spectral Studies ◽  
Ftir Analysis ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Phase Spinel ◽  
Uv Visible ◽  
Co Precipitation

The device formation in current technology demands effective magnetic materials. Cobalt ferrite nanoparticles were synthesized by the co–precipitations method using the precursor materials (Fe(No3)3 9H2O) and (Co(NO3)2 6H2O). X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) analysis, and UV–Visible absorption spectral studies were used to analyze the structural, chemical/functional groups with possible stretching and optical bandgap properties of the CoFe2O4 powder. XRD results designate that the resultant particles are crystalline, pure single-phase spinel structure. From the FTIR analysis reveals that C-C, C=O stretching, and the shift is leaked indicating that the presence CoFe2O4. The absorption and the optical band gaps values are increased trend with temperatures also evidence that is enhancing magnetic behavior.

scholarly journals Effect of Silica Embedding on the Structure, Morphology and Magnetic Behavior of (Zn0.6Mn0.4Fe2O4)δ/(SiO2)(100−δ) Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2232
Author(s):  
Thomas Dippong ◽  
Iosif Grigore Deac ◽  
Oana Cadar ◽  
Erika Andrea Levei
Keyword(s):  
Crystallite Size ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Average Crystallite Size ◽  
Chemical Transformations ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Crystallite Sizes ◽  
Ft Ir

The effect of SiO2 embedding on the obtaining of single-phase ferrites, as well as on the structure, morphology and magnetic properties of (Zn0.6Mn0.4Fe2O4)δ(SiO2)100−δ (δ = 0–100%) nanoparticles (NPs) synthesized by sol-gel method was assessed. The phase composition and crystallite size were investigated by X-ray diffraction (XRD), the chemical transformations were monitored by Fourier transform infrared (FT-IR) spectroscopy, while the morphology of the NPs by transmission electron microscopy (TEM). The average crystallite size was 5.3–27.0 nm at 400 °C, 13.7–31.1 nm at 700 °C and 33.4–49.1 nm at 1100 °C. The evolution of the saturation magnetization, coercivity and magnetic anisotropy as a function of the crystallite sizes were studied by vibrating sample magnetometry (VSM) technique. As expected, the SiO2 matrix shows diamagnetic behavior accompanied by the accidentally contribution of a small percent of ferromagnetic impurities. The Zn0.6Mn0.4Fe2O4 embedded in SiO2 exhibits superparamagnetic-like behavior, whereas the unembedded Zn0.6Mn0.4Fe2O4 behaves like a high-quality ferrimagnet. The preparation route has a significant effect on the particle sizes, which strongly influences the magnetic behavior of the NPs.

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