Synthesis and magnetic characterization of Zn0.6Ni0.4Fe2O4 nanoparticles via a polyethylene glycol-assisted hydrothermal route

Sertkol, M.; Köseoğlu, Yüksel; Baykal, A.; Kavas, H.; Basaran, Ali C.

doi:10.1016/j.jmmm.2008.08.083

Cited by 122 publications

(48 citation statements)

References 57 publications

(55 reference statements)

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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: 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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Section: Magnetic Studiesmentioning

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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“…The saturation magnetization of these samples was smaller than that observed for the bulk material though (∼80 emu·g −1 ) [12,14]. These differences in the magnetization value (such as saturation magnetization, remanent magnetization, and coercivity) between the nanosized ferrites and bulk ferrites can be attributed to the finite size effect [19]. Additionally, the lack of oxygen to mediate the superexchange mechanism between nearest iron ions on the surface can lead to a decrease in exchange coupling, resulting in slanted spins and a decrease in the nanoparticles' saturation magnetization [20].…”

Section: Resultsmentioning

confidence: 66%

Magnetic Properties of Co_0.5Zn_0.5Fe₂O₄Nanoparticles Synthesized by a Template-Assisted Hydrothermal Method

2011

Journal of Nanotechnology

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In the present paper, nickel cobalt ferrite (Co 0.5 Zn 0.5 Fe 2 O 4 ) nanoparticles were synthesized using a template-assisted hydrothermal method. Carboxymethyl cellulose was used as the templating agent for controlling the morphology of the Co 0.5 Zn 0.5 Fe 2 O 4 nanoparticles. The synthesized nanoparticles were characterized using X-ray diffraction, scanning electron microscopy, and a vibrating sample magnetometer. The results indicated that the morphology of the nanoparticles changed from granular and superparamagnetic to platelike and ferromagnetic with the addition of the template. The Co 0.5 Zn 0.5 Fe 2 O 4 nanoparticles synthesized without the template exhibited a saturation magnetization and coercivity 2.81 T and 0.2 kA·m −1 , while when the template was used, the saturation magnetization and coercivity increased to 3.13 T and 76.6 kA·m −1 as the template proportion increased to 0.3.

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“…Then, the A sites of the nickel-ferrites are likely to mostly be occupied by Fe 3+ ions, exhibiting inverse-spinel nature. Such octahedral preference of Ni 2+ ions was reported in a number of nickel-ferrite systems [10][11][12]. When Ni 2+ ion subsists at the B site, its ionic radius is known to be about 0.083 nm, significantly smaller than that of the octahedral Fe 2+ ion (0.092 nm) [13].…”

Section: +mentioning

confidence: 69%

Structural Phase Transition, Electronic Structure, and Magnetic Properties of Sol-gel-prepared Inverse-spinel Nickel-ferrites Thin Films

Kim¹,

Kim²,

Kim³

2014

Journal of Magnetics

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X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM) were used to investigate the influence of Ni ions on the structural, electronic, and magnetic properties of nickelferrites (Ni x Fe 3-x O 4 ). Spinel Ni x Fe 3-x O 4 (x ≤ 0.96) samples were prepared as polycrystalline thin films on Al 2 O 3 (0001) substrates, using a sol-gel method. XRD patterns of the nickel-ferrites indicate that as the Ni composition increases (x > 0.3), a structural phase transition takes place from cubic to tetragonal lattice. The XPS results imply that the Ni ions in Ni x Fe 3-x O 4 substitute for the octahedral sites of the spinel lattice, mostly with the ionic valence of +2. The minority-spin d-electrons of the Ni 2+ ions are mainly distributed below the Fermi level (E F ), at around 3 eV; while those of the Fe 2+ ions are distributed closer to E F (~1 eV below E F ). The magnetic hysteresis curves of the Ni x Fe 3-x O 4 films measured by VSM show that as x increases, the saturation magnetization (M s ) linearly decreases. The decreasing trend is primarily attributable to the decrease in net spin magnetic moment, by the Ni 2+ (2 µ B ) substitution for octahedral Fe 2+ (4 µ B ) site.

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Synthesis and magnetic characterization of Zn0.6Ni0.4Fe2O4 nanoparticles via a polyethylene glycol-assisted hydrothermal route

Cited by 122 publications

References 57 publications

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

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

Magnetic Properties of Co_0.5Zn_0.5Fe₂O₄Nanoparticles Synthesized by a Template-Assisted Hydrothermal Method

Structural Phase Transition, Electronic Structure, and Magnetic Properties of Sol-gel-prepared Inverse-spinel Nickel-ferrites Thin Films

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Synthesis and magnetic characterization of Zn0.6Ni0.4Fe2O4 nanoparticles via a polyethylene glycol-assisted hydrothermal route

Cited by 122 publications

References 57 publications

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

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

Magnetic Properties of Co0.5Zn0.5Fe2O4Nanoparticles Synthesized by a Template-Assisted Hydrothermal Method

Structural Phase Transition, Electronic Structure, and Magnetic Properties of Sol-gel-prepared Inverse-spinel Nickel-ferrites Thin Films

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Magnetic Properties of Co_0.5Zn_0.5Fe₂O₄Nanoparticles Synthesized by a Template-Assisted Hydrothermal Method