Eco-environmental synthesis and characterization of nanophase powders of Co, Mg, Mn and Ni ferrites

Ghercă, Daniel; Pui, Aurel; Nica, Valentin; Caltun, Ovidiu Florin; Cornei, Nicoleta

doi:10.1016/j.ceramint.2014.02.036

Cited by 48 publications

(19 citation statements)

References 32 publications

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“…It is noted the occupation of metallic cations (Ni þ 2 , Mg þ 2 , Mn þ 2 , Co þ 2 and Fe þ 3 ) simultaneously in tetrahedral (A) and octahedral (B) sites of both formed structures. Therefore, the XRD analysis, associated with the Rietveld refinement, confirmed the inverse spinel feature of these materials [12,13,19] Fig. 3, we observe the dependence of the magnetization with the applied magnetic field by means of the hysteresis cycle.…”

Section: Resultssupporting

confidence: 76%

Correlation between coercive field and radiation attenuation in Ni and Mg ferrite doped with Mn and Co

Silva

Nasar

et al. 2015

Journal of Magnetism and Magnetic Materials

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a b s t r a c tIt was investigated NiMg 0.1 M x Fe 2 O 4 ferrite where M stands for Mn, Co or simultaneously Mn and Co dopants. The concentration of M is 0.1 and it was divided by two in the sample with addition of Mn and Co. It was used the method of citrate precursors with 1100°C calcination. The materials were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and reflectivity measures by waveguide method. The X-ray diffraction measures, with Rietveld refinement, present average crystallite sizes between 0.576 and 0.626 mm. The SEM analysis shows clustered particles smaller than 1 mm at 1100°C, in agreement with Rietveld refinement. The compositions with Mn reach magnetization between 42.09 and 53.20 Am 2 /kg, which does not generate high microwave absorption. The 0.1 Co addition reached greater coercivity (2.96 Â 10 À 2 T), with up to 84% reflectivity at 10.17 GHz frequency. The Co material has high magnetocrystalline anisotropy, which is associated with the increase of coercive field, H c . The higher coercivity optimizes the reflectivity results.

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Section: Resultssupporting

confidence: 76%

Correlation between coercive field and radiation attenuation in Ni and Mg ferrite doped with Mn and Co

Silva

Nasar

et al. 2015

Journal of Magnetism and Magnetic Materials

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“…Several chemical, physical and mechanochemical methods are used in the literature to synthesize NiFe 2 O 4 nanoparticles such as hydrothermal reaction, co-precipitation, sol-gel method and ball milling [18][19][20][21][22]. In particular, the sol-gel method is a versatile technique to vary the properties of different transition metal oxides by controlling different parameters such as temperature, time of reaction, pH of the medium and the reagent's concentration [23].…”

Section: Introductionmentioning

confidence: 99%

Cation distribution and enhanced surface effects on the temperature-dependent magnetization of as-prepared NiFe2O4 nanoparticles

Nadeem

Siddique

2015

Appl. Phys. A

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Nickel ferrite, i.e., NiFe 2 O 4 , nanoparticles are synthesized by sol-gel method using urea as a neutralizing agent. The formation of spinel phase and crystal structure of the as-prepared sample is analyzed by X-ray diffraction and transmission electron microscope. In order to confirm phase formation and cation arrangement, room temperature 57 Fe Mössbauer spectroscopy is employed. The degree of inversion (i) estimated from the relative peak area is found to be 0.6, which confirms a mixed spinel structure of the asprepared sample. Zero-field-cooled/field-cooled measurements showed evidence of superparamagnetic behavior associated with the nanosized particles. Hysteresis loop measurements revealed temperature-dependent magnetic properties: The coercive field (H C ) decreases with increasing temperature and deviates from the Kneller's law for ferromagnetic nanostructures; and the saturation magnetization (M s ) follows modified Bloch's law in the temperature range between 25 and 400 K. However, below 25 K, an abrupt increase in magnetization of nanoparticles is observed. In order to understand this behavior, an additional contribution has to be added to the core magnetization to properly fit the data. Hence, a surface correction term to the Bloch's law is found to describe the temperature dependence of magnetization in the core-shell NiFe 2 O 4 nanoparticles.

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“…Based on the comparison of the M s value with the previously reported results, all the assynthesized ferrite nanocrystals exhibit excellent magnetic properties with higher saturation magnetization. [17][18][19][20][21] Whereas, due to their small particle size and surface effects, the M s values for MFe 2 O 4 nanoparticles, as compared to those of their corresponding bulk counterparts, are lower. To confirm the superparamagnetic properties of NiFe 2 O 4 and MnFe 2 O 4 nanoparticles, ZFC and FC curves of three representative samples measured in an applied magnetic field of 100 Oe are given in Fig.…”

mentioning

confidence: 99%

Microstructure and magnetic properties of MFe2O4 (M = Co, Ni, and Mn) ferrite nanocrystals prepared using colloid mill and hydrothermal method

Wang

Ding

Zhao

et al. 2015

Journal of Applied Physics

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Three kinds of spinel ferrite nanocrystals, MFe2O4 (M = Co, Ni, and Mn), are synthesized using colloid mill and hydrothermal method. During the synthesis process, a rapid mixing and reduction of cations with sodium borohydride (NaBH4) take place in a colloid mill then through a hydrothermal reaction, a slow oxidation and structural transformation of the spinel ferrite nanocrystals occur. The phase purity and crystal lattice parameters are estimated by X-ray diffraction studies. Scanning electron microscopy and transmission electron microscopy images show the morphology and particle size of the as-synthesized ferrite nanocrystals. Raman spectrum reveals active phonon modes at room temperature, and a shifting of the modes implies cation redistribution in the tetrahedral and octahedral sites. Magnetic measurements show that all the obtained samples exhibit higher saturation magnetization (Ms). Meanwhile, experiments demonstrate that the hydrothermal reaction time has significant effects on microstructure, morphologies, and magnetic properties of the as-synthesized ferrite nanocrystals.

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Eco-environmental synthesis and characterization of nanophase powders of Co, Mg, Mn and Ni ferrites

Cited by 48 publications

References 32 publications

Correlation between coercive field and radiation attenuation in Ni and Mg ferrite doped with Mn and Co

Correlation between coercive field and radiation attenuation in Ni and Mg ferrite doped with Mn and Co

Cation distribution and enhanced surface effects on the temperature-dependent magnetization of as-prepared NiFe2O4 nanoparticles

Microstructure and magnetic properties of MFe2O4 (M = Co, Ni, and Mn) ferrite nanocrystals prepared using colloid mill and hydrothermal method

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