Dielectric behavior and ac electrical conductivity study of Sm3+ substituted Mg–Zn ferrites

Melagiriyappa, E.; Jayanna, H. S.; Chougule, B.K.

doi:10.1016/j.matchemphys.2008.05.014

Cited by 115 publications

(38 citation statements)

References 17 publications

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“…All the samples are found to exhibit an increase in r with frequency and agree with the reported [80,81] trends in other ferrites. It is noticed that the conduction mechanism in ferrites is explained [82] on the basis of hopping of charge carriers, which are confined between the Fe 2?…”

supporting

confidence: 88%

Experimental characterization of nanocrystalline niobium-doped nickel–zinc ferrites: occurrence of superparamagnetism

Lakshmi¹,

Sridhar

Govindraj

et al. 2016

J Mater Sci

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Structural, morphological, magnetic, and dielectric investigations are carried out in Nb-doped (viz., for x equal to 0.0-0.4 by wt%) nanocrystalline Ni-Zn ferrites synthesized by hydrothermal method. XRD, IR studies infer the growth of nano structures and Fe 2 O 3 phase. Nb ions segregate at grain boundaries. Crystallite size (D) varies from 62 to 18 nm with x. FTIR absorption exhibits split at higher x. Saturation magnetization witnesses an overall decrease with x. Trends of M s (x) are explained by nature of dopant, preferential replacement, surface canting (Y-K angles) and lattice contraction. Variations of coercive field (H c ) and D infer singledomain to multi-domain morphological transformation. Occurrence of superparamagnetism (SPM) is predicted for zeroed values of H c and for a critical concentration x crit equal to 0.321. Enhanced Nb 5? -Fe 2? binding with dopant (x up to 0.2) results for decrease in dielectric constant e 0 r , loss factor tand and increase in resistivity q. Lowered ac conductivity is attributed to blockade of path by Nb 5? ions in the vicinity of B-sites. Relatively higher q (*10 8 X cm) and lower loss (tand *10 -2 -10 -3 ) evinced for 10 kHz. Enhanced core loss is realized with x manifested as lowered H c and tand to usher their utility in high-frequency applications.

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supporting

confidence: 88%

Experimental characterization of nanocrystalline niobium-doped nickel–zinc ferrites: occurrence of superparamagnetism

Lakshmi¹,

Sridhar

Govindraj

et al. 2016

J Mater Sci

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“…ions, is responsible for electrical conduction in mixed ferrites. Conduction mechanism in ferrites is similar to that of the dielectric polarization [30]. Increase in ac conductivity with increase in Dy content can be explained on the basis of electron exchange mechanism between Fe 3?…”

Section: Dielectric Propertiesmentioning

confidence: 67%

Compositional variation of structural, electrical and magnetic properties of Dy substituted Ni–Co spinel ferrite

Kadam

Rajpure

2016

J Mater Sci: Mater Electron

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In the present work nanocrystalline dysprosium substituted Ni 0.8 Co 0.2 Fe 2-x Dy x O 4 (x = 0.00, 0.025, 0.050, 0.075 & 0.1) ferrite system was synthesized by the solution combustion method. The phase formation has been confirmed by Reitveld analysis of XRD patterns, which is a characteristic of spinel ferrite with most intense (311) peak. The bond lengths and site radii of tetrahedral and octahedral sites are found to increase with increase in Dy content. IR measurements showed two prominent bands which are common characteristics of spinel ferrite. The surface morphology shows spherical grains of increasing size with increase in Dy content. The dielectric measurements show the usual dielectric dispersion due to space charge polarization. The electrical resistivity of Ni-Co ferrites is found to increase with Dy content. This can be explained on the basis of formation of DyFeO 3 secondary phase along with spinel lattice. Complex impedance spectra show incomplete semicircles due to the high resistance values at low frequency. Magnetic measurements reveal low coercive field with increase in Dy content. Low coercive fields suggest the use of these materials in data storage and magnetic shielding devices.

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“…It is well known as soft magnetic n-type semi conductive material, with high resistivity and low magnetic and dielectric losses. Among various ferrites, magnesium ferrite (MgFe 2 O 4 ) enjoys a special attention because of its vast applications such as one of the candidates for high density magnetic recording [4][5][6][7][8] , microwave absorbents, sensors and electronic device, high frequency devices, color imaging 9-11 and fabrication of radio frequency coils, transformer cores and chock coils, noise filters, recording heading and rod antennas 12,13 . Magnesium ferrites are the potential materials for various applications due to their high electrical resistivity, low magnetic and dielectric losses 14,15 .…”

Section: Research Articlementioning

confidence: 99%

Synthesis of Spinel MgFe2O4 Ferrite Material and Studying its Structural and Morphological Properties Using Solid State Method

2017

Chem Sci Trans

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Abstract:MgFe 2 O 4 ferrite has excellent magnetic behavior and high resistive material. The properties of Mg ferrite were investigated by solid state reaction method. In this work, our aim is to synthesize MgFe 2 O 4 using oxide precursors (i.e. MgO and Fe 2 O 3 ). The samples were pre-calcined at 800 o C for 5 hours and calcined at 1000 o C for 6 hours and have the single phase cubic spinel structure. The phase composition, micro-morphology, elemental analysis and Wyckoff sites of the products of Mg-Fe-O system were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared (FTIR), respectively. Spinel Mg ferrite belongs to Fd-3m space group. From the XRD result the crystallite size, lattice constant and cell volume of MgFe 2 O 4 was found to be 44.94 nm, 8.426Å and 598, respectively. From SEM result the magnesium ferrite particle size formed was ranged from 251 nm to 414 nm in diameter for the given alcinations temperature at 1000 °C. The EDS spectra confirm the presence of Fe, Mg and O in the compound. In FT-IR analysis vibrations of ions in the crystal lattice of Mg ferrite observed in the range of 1200-400 cm -1 and the high-frequency band (ν 1 ) lies in the 650-530 cm -1 range and the low-frequency band (ν 2 ) in the 446-400 cm -1 range.

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Dielectric behavior and ac electrical conductivity study of Sm3+ substituted Mg–Zn ferrites

Cited by 115 publications

References 17 publications

Experimental characterization of nanocrystalline niobium-doped nickel–zinc ferrites: occurrence of superparamagnetism

Experimental characterization of nanocrystalline niobium-doped nickel–zinc ferrites: occurrence of superparamagnetism

Compositional variation of structural, electrical and magnetic properties of Dy substituted Ni–Co spinel ferrite

Synthesis of Spinel MgFe2O4 Ferrite Material and Studying its Structural and Morphological Properties Using Solid State Method

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