Low temperature hydrothermal synthesis and characterization of Mn doped cobalt ferrite nanoparticles

Köseoğlu, Yüksel; Alan, Furkan; Tan, Muhammed; Yilgin, Resul; Öztürk, Mustafa Kemal

doi:10.1016/j.ceramint.2012.01.001

Cited by 298 publications

(86 citation statements)

References 44 publications

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“…From the M-H loop, it can be observed that the spinel Mn 0.5 Co 0.5 Fe 2 O 4 nanoparticles show high saturation magnetization (M s ) justified by the high anisotropy and small dimensions of the grains. The M s value of pure CoFe 2 O 4 is 55.16 ± 24 emu/g, which is lower than that of the earlier reported values, i.e., 59.0 emu/g [8] and 93.9 emu/g (bulk) [46]. The observed difference in the value of M s might be due to particle size, crystalline nature and arrangement of the particles, as well as the nature and composition of the dopant.…”

Section: Photoluminescence Spectroscopycontrasting

confidence: 81%

“…(M s = 80 emu/g) at room temperature [6][7][8]. However, different values of H c and M s have been reported [9,10] for nanosized CoFe 2 O 4 particles, due to the fact that the magnetic property may depend on the particle size and preparation methods.…”

mentioning

confidence: 95%

“…Moreover, Mn 2+ doped CoFe 2 O 4 is quite unstable in air, and Mn 2+ ions on the surface oxidize to form Mn 3+ ions, resulting in the dissociation of the ferrites at elevated temperatures (200 − 1000 • C) [19]. Therefore, the above-said methods involving higher temperatures are not suitable for the preparation of Mn 2+ doped CoFe 2 O 4 nanostructures [8].…”

mentioning

confidence: 98%

See 2 more Smart Citations

Role of Mn2+ Doping on Structural, Morphological, and Opto-Magnetic Properties of Spinel Mn x Co1−x Fe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) Nanocatalysts

Manikandan

Durka²,

Antony

2015

J Supercond Nov Magn

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Spinel Mn x Co 1−x Fe 2 O 4 ; x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) nanoparticles were synthesized by ureaassisted auto combustion method using nitrates of Co, Mn and Fe as the starting materials and urea as the fuel. X-ray diffraction (XRD) analysis showed that all composition was found to have a cubic spinel structure. The average crystallite size of the samples was estimated using the Debye-Scherrer formula and was found to be in the range of 22.62 and 36.45 nm. The lattice parameter increased from 8.432 to 8.457Å with increasing the Mn 2+ content, which was determined by Rietveld analysis. High-resolution scanning electron microscopy (HR-SEM) and high-resolution transmission electron microscopy (HR-TEM) analyses were used to study the morphological variation, and the results showed a nanosized particlelike morphology. Energy-dispersive X-ray (EDX) results showed that the composition of the elements was relevant as expected from the synthesis. The bandgap energy of the pure CoFe 2 O 4 was estimated to be 2.33 eV from UV-visible diffuse reflectance spectroscopy (DRS). With the increase of Mn 2+ ion, the bandgap energy increased from 2.35 to 2.42 eV. The magnetic properties of the A. Manikandan ( ) · S. samples were investigated at room temperature by using a vibrating sample magnetometer (VSM). The magnetic hysteresis (M-H) loop confirmed the superparamagnetic nature of pure CoFe 2 O 4 and a weak ferromagnetic behavior of Mn 2+ doped CoFe 2 O 4 samples with specific saturation magnetization in the range of 55.16 ± 24 and 66.92 ± 05 emu/g. All compositions of spinel Mn x Co 1−x Fe 2 O 4 samples were successfully tested as catalyst for the conversion of benzyl alcohol, which has resulted in 62.75 and 92.62 % conversion efficiency of CoFe 2 O 4 and Mn 0.5 Co 0.5 Fe 2 O 4 , respectively.

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Section: Photoluminescence Spectroscopycontrasting

confidence: 81%

mentioning

confidence: 95%

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Role of Mn2+ Doping on Structural, Morphological, and Opto-Magnetic Properties of Spinel Mn x Co1−x Fe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) Nanocatalysts

Manikandan

Durka²,

Antony

2015

J Supercond Nov Magn

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“…It can be seen that the coinciding broad maximum observed on the ZFC curve occurs at a slightly lower temperature T m than T irr . Such behavior usually signalizes a certain particle size distribution in the nanomaterials; while a fraction of the largest particles already freeze at T irr , the majority of fraction of the nanoparticles in the sample is being blocked at T m resulting in a distribution of the blocking temperatures T B in the sample [32,33]. Figure 4 shows the field-dependent magnetization of the as-prepared NiFe 2 O 4 nanoparticles measured at different temperatures.…”

Section: Magnetic Studiesmentioning

confidence: 96%

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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“…5 that the peak in the ZFC curves becomes broader with increasing Ni concentration. Since the broadness of the peak in ZFC curve was associated with particle size distribution, therefore the broad peak observed in our samples indicated distribution of particle sizes [40].…”

Section: Magnetic Propertiesmentioning

confidence: 98%

Sol–gel synthesis of nanocrystalline Zn1−xNixFe2O4 ceramics and its structural, magnetic and dielectric properties

Atif

Nadeem

2014

J Sol-Gel Sci Technol

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Zn 1-x Ni x Fe 2 O 4 (0.0 B x B 1.0) nanoparticles are prepared by sol-gel method using urea as a neutralizing agent. The evaluation of XRD patterns and TEM images indicated fine particle nature. The average crystallite size increased from 10 to 24 nm, whereas lattice parameters and density decreased with increasing Ni content (x). Infrared spectra showed characteristic features of spinel structure along with a strong influence of compositional variation. Magnetic measurements reveal a maximum saturation magnetization for Zn 0.5 Ni 0.5 Fe 2 O 4 (x = 0.5); however, reduced value of magnetization is attributed to the canted spin structure and weakening of Fe 3? (A)-Fe 3? (B) interactions at the surface of the nanoparticles. Impedance analysis for different electro-active regions are carried out at room temperature with Ni substitution. The existence of different relaxations associated with grain, grain boundaries and electrode effects are discussed with composition. It is suggested that x = 0.5 is an optimal composition in Zn 1-x Ni x Fe 2 O 4 system with moderate magnetization, colossal resistivity and high value of dielectric constant at low frequency for their possible usage in field sensor applications.

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Low temperature hydrothermal synthesis and characterization of Mn doped cobalt ferrite nanoparticles

Cited by 298 publications

References 44 publications

Role of Mn2+ Doping on Structural, Morphological, and Opto-Magnetic Properties of Spinel Mn x Co1−x Fe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) Nanocatalysts

Role of Mn2+ Doping on Structural, Morphological, and Opto-Magnetic Properties of Spinel Mn x Co1−x Fe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) Nanocatalysts

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

Sol–gel synthesis of nanocrystalline Zn1−xNixFe2O4 ceramics and its structural, magnetic and dielectric properties

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