Magnetic properties of bulk and nanosized ferrites

Msomi, J. Z.; Moyo, T.; Doyle, T. B.

doi:10.1016/j.jmmm.2006.11.141

Cited by 25 publications

(13 citation statements)

References 3 publications

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“…At a critical grain size single domain particles can be expected to transform to multidomain particles with increase in the sintering temperature. Similar behavior has been observed due to the effect of milling on coercive fields as grain sizes reduce [9].…”

Section: Resultssupporting

confidence: 80%

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Synthesis and magnetic properties of Cu0.5Ni0.5Fe2O4 nanoparticles produced by glycothermal and hydrothermal processes

Msomi

Moyo

2009

Hyperfine Interact

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Cu 0.5 Ni 0.5 Fe 2 O 4 nanoparticles have been synthesized in ethylene glycol solution and in deionised water. The glycothermal reaction was carried at 200 • C under gauge pressure of 100 psi. The hydrothermal treatment was done at 100 • C under zero pressure. Complete single-phase cubic spinel structure in the samples made by glycothermal (sample G) and hydrothermal (sample H) processes formed after annealing at 600 • C and 900 • C respectively. The coercive field of sample H increases from 72 Oe to 133 Oe after sintering at 700 • C and then decrease to 11 Oe on sintering at 1000 • C. This variation is attributed to surface effects and crossover from single to multidomain behavior due to increasing particle size.

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Section: Resultssupporting

confidence: 80%

“…This disappears after sintering the sample at 900 • C. The narrowing of the peaks with increasing annealing temperature reflects increasing grain size. The grain sizes can be calculated from the broadening of the 311 XRD peak using the Scherrer formula [1,7,9]. The variation of grains size with sintering temperature is plotted in Fig.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and magnetic properties of Cu0.5Ni0.5Fe2O4 nanoparticles produced by glycothermal and hydrothermal processes

Msomi

Moyo

2009

Hyperfine Interact

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“…The measurements of hyperfine fields in ferrite materials have been routinely obtained in previous works [1][2][3][4][5][6][7][8][9][10]. However the temperature analysis of the hyperfine fields as a function of temperature (B hf (T)) has not been exhaustive [1][2][3][4][5][6][7][8].…”

Section: The Intrasublattice Interactions (A-o-a) and (B-o-b)mentioning

confidence: 99%

“…However the temperature analysis of the hyperfine fields as a function of temperature (B hf (T)) has not been exhaustive [1][2][3][4][5][6][7][8].…”

Section: The Intrasublattice Interactions (A-o-a) and (B-o-b)mentioning

confidence: 99%

Temperature dependence of the hyperfine fields in NiFe2O4 and CuFe2O4 oxides

Msomi

Moyo

2007

Hyperfine Interact

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We report the temperature dependence of the magnetic properties of (Ni, Cu)Fe 2 O 4 spinel oxides. Mössbauer spectra for NiFe 2 O 4 at various temperatures (79 ≤ T ≤ 900 K) are well fitted by two sextets associated with 57 Fe nuclei at tetrahedral (A) and octahedral (B) sites. The Curie point T C was deduced by zero velocity Mössbauer technique to be 873 ± 3 K. The hyperfine fields are observed to vary with temperature according to the equationwhere n = 1 (based on the Landau-Ginzburg theory) and n = 2 (based on the Stoner theory). A systematic decrease of the Mössbauer spectrum shift with increasing temperature is observed. KeywordsFerrites · Mössbauer spectroscopy · Hyperfine fields Ferrites are a group of oxides with the spinel crystal structure AB 2 O 4 , where A and B cations are contained in the tetrahedral (A) and octahedral (B) sites. The magnetic order depends on different superexchange interactions mediated by intervening oxygen ions. The superexchange interactions are characterized by the exchange integrals J AB (A-O-B), J AA (A-O-A) and J BB (B-O-B). Ferrimagnetic ordering takes place when the intersublattice interaction (A-O-B) is stronger than

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“…NiCuZn ferrites have better high frequency properties compared to that of other ferrites. It has low sintering temperature (< 950°C) and good electromagnetic properties [1][2]. Also these ferrites have low densification temperatures compared to NiZn ferrites [1,3].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Nanocrystalline CuNiZn Ferrite Powder Through Sol-gel Auto Combustion Method

Mahanavar¹

2018

IJRASET

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The ferrite powders of nominal composition Cu0.5ZnxNi0.5-xFe2O4 were synthesised by sol-gel auto combustion method using citric acid as an oxidising agent and the values of x are varied as x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5. The process resulted in the formation of nano-sized, highly uniform powders. The ferrite powders were sintered at 1000 0 C. These synthesized and heat treated powders were investigated for their structural properties such as phase purity and particle size. The average grain size obtained from XRD data in the heat treated samples is in the nano range. The ferrites are found to be soft ferrites as revealed from hysteresis data. Also, the coercively and retentivity values are small. These soft ferrites can be used for various electrical and magnetic applications.

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Magnetic properties of bulk and nanosized ferrites

Cited by 25 publications

References 3 publications

Synthesis and magnetic properties of Cu0.5Ni0.5Fe2O4 nanoparticles produced by glycothermal and hydrothermal processes

Synthesis and magnetic properties of Cu0.5Ni0.5Fe2O4 nanoparticles produced by glycothermal and hydrothermal processes

Temperature dependence of the hyperfine fields in NiFe2O4 and CuFe2O4 oxides

Synthesis and Characterization of Nanocrystalline CuNiZn Ferrite Powder Through Sol-gel Auto Combustion Method

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