Magnetic properties of nanophase CoFe2O4 particles

Blaskov, V.; Petkov, V.; Rusanov, V.; Martínez, Laura Martínez; Martı́nez, B.; Muñoz, J.S.; Mikhov, M.

doi:10.1016/s0304-8853(96)00277-6

Cited by 110 publications

(72 citation statements)

References 21 publications

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“…Magnetite nanoparticles were prepared according to a previously reported method [9][10][11]: 5.80 g of FeCl 3 ·6H 2 O and 2.15 g of FeCl 2 ·4H 2 O were dissolved in 200 mL of deionized water in a round bottom flask placed in an ultrasonic bath with mechanical stirring at 70-80 • C. 10 mL of 25% NH 4 OH were quickly added to the solution. After a few seconds the solution turned black (typical magnetite color) and 10 mL of oleic acid were added to the suspension stirring vigorously for 2 h. The black fine magnetite precipitate was separated from the solution using a magnet and washed several times with hot deionized water and acetone to remove non reacted metallic salts and excess of oleic acid respectively.…”

Section: Synthesis Of Nanoparticlesmentioning

confidence: 99%

“…The synthesis of ferrite nanoparticles has been intensively investigated in recent years because of their electrical and magnetic properties. Many procedures have been explored: chemical coprecipitation [9][10][11], co-precipitation in reverse microemulsions [12,13], hydrothermal synthesis, sol-gel techniques [14], use of citrate precursors [15], mechanical mixing [16] and thermal decomposition in solid matrices [17] are some examples. Nevertheless, the simplest and cheapest ways to obtain nano-sized ferrites are chemical co-precipitation and the use of inverse microemulsions.…”

Section: Introductionmentioning

confidence: 99%

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Magnetic nanocomposites based on hydrogenated epoxy resin

González

Martín-Fabiani

Baselga

et al. 2012

Materials Chemistry and Physics

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A hydrogenated derivative of diglycidylether of bisphenol A (HDGEBA) has been successfully employed to prepare magnetic thermosetting nanocomposites. Magnetite nanoparticles of ≈10 nm modified with oleic acid were synthesized by co-precipitation of ferric and ferrous salts in ammonium solutions. Nanocomposites with amounts up to 5% ww −1 of nanoparticles were dispersed in HDGEBA by co-solvent method and cured with m-xylilendiamine. Both the particles and nanocomposites were characterized by FTIR, DSC, TGA, XRD, TEM, DMTA and VSM. Due to the lower polarity of the hydrogenated resin, the enhanced compatibility with magnetite oleic coverage allowed obtaining good dispersions of the nanoparticles for compositions up 1% ww −1 , while at higher concentration agglomerates were observed. Two behaviors in the thermal properties were obtained: for compositions below 1% ww −1 the glass tran-sition temperature increased with the amount of nanoparticles, whereas for higher amounts the glass transition temperature decreased. Superparamagnetic behavior was observed in both the particles and the nanocomposites; the blockage temperature gradually increases with loading but it is lower than the observed for bulk magnetite nanoparticles. This fact reflects that nanoparticle-nanoparticle distances in the nanocomposites gradually decrease with loading which is in accordance with a good dispersion state for low loadings and the presence of aggregates at high loadings.

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Section: Synthesis Of Nanoparticlesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Magnetic nanocomposites based on hydrogenated epoxy resin

González

Martín-Fabiani

Baselga

et al. 2012

Materials Chemistry and Physics

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“…The degree of inversion thus depends on the thermal history. Cobalt ferrite has been regarded a competitive candidates for use in high-density magnetic recording media as a result of its high coercivity, moderate saturation magnetization, remarkable chemical stability, and mechanical hardness [1][2][3]. When manganese ferrite, MnFe 2 O 4 , is prepared at high temperatures (> 1,173 K), 20 % of the Mn 2+ ions migrate from A to the B sites, and this means that MnFe 2 O 4 may be characterized as a mixture of normal and inverse spinel ferrite.…”

Section: Introductionmentioning

confidence: 99%

Nickel Substitution Effects on Nano-sized Co, Mn and MnZn Ferrites Synthesized by Sol-gel Method

Choi¹,

Kwon²,

Chae³

et al. 2016

Journal of Magnetics

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“…Cobalt ferrite, CoFe 2 O 4 , is a hard magnetic material with a high coercivity, moderate saturation magnetization, and remarkable chemical stability and mechanical hardness [1,2]. Cobalt ferrite basically has an inverse spinel structure with a corrected cation distribution of (Co 0.1 Fe 0.9 )-[Co 0.9 Fe 1.1 ]O 4 , and the degree of inversion depends on the thermal history of the sample.…”

Section: Introductionmentioning

confidence: 99%

Effects of Ga Substitution on Crystallographic and Magnetic Properties of Co Ferrites

Chae¹,

Choi²,

Kang³

et al. 2015

Journal of Magnetics

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The crystallographic and magnetic properties of gallium-substituted cobalt ferrite (CoGa x Fe 2-x O 4 ) were investigated. The new material was synthesized using conventional ceramic methods, with gallium substituted for ferrite in the range of x = 0.0 to 1.0, in steps of 0.2. X-ray diffraction and Mössbauer spectroscopy were used to confirm the presence of crystallized particles in the CoGa x Fe 2-x O 4 ferrite powders. All of the samples exhibited a single phase with a spinel structure, and the lattice parameters decreased as the gallium content increased. The particle size of the samples also decreased as gallium increased. For x ≤ 0.4, the Mössbauer spectra of CoGa x Fe 2-x O 4 could be fitted with two Zeeman sextets, which are the typical spinel ferrite spectra of Fe 3+ with A-and B-sites. However, for x ≥ 0.6, the Mössbauer spectra could be fitted with two Zeeman sextets and one doublet. The variation in the Mössbauer parameters and the absorption area ratio indicated a cation distribution of (Co 0.2-0.2x Ga x Fe 0.8-0.6x )[Co 0.8+0.2x Fe 1.2-0.4x ]O 4 , and the magnetic behavior of the samples suggested that the increase in gallium content led to a decrease in the saturation magnetization and in the coercivity.

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Magnetic properties of nanophase CoFe2O4 particles

Cited by 110 publications

References 21 publications

Magnetic nanocomposites based on hydrogenated epoxy resin

Magnetic nanocomposites based on hydrogenated epoxy resin

Nickel Substitution Effects on Nano-sized Co, Mn and MnZn Ferrites Synthesized by Sol-gel Method

Effects of Ga Substitution on Crystallographic and Magnetic Properties of Co Ferrites

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