Dielectric properties of polycrystalline Cu–Zn ferrites at microwave frequencies

Lamani, Ashok R.; Jayanna, H. S.; Parameswara, P.; Somashekar, R.; Ramachander,; Rao, R. Srihari; Prasanna, G D

doi:10.1016/j.jallcom.2011.02.132

Cited by 10 publications

(3 citation statements)

References 14 publications

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“…Dispersions of such magnetic nanoparticles are popularly known as ferro fluids and their emulsions are easy to manipulate with external magnetic field and hence they are extensively used for various fundamental studies [1][2][3][4] and technological applications such as optical devices [5], coolants [6,7] sensors [8,9] in biomedical applications, e.g. magnetically guided drug delivery, magnetic resonance image (MRI) contrast agent and cancer therapy [10,11].…”

Section: Introductionmentioning

confidence: 99%

Structure and magnetic properties of Cd doped copper ferrite

Rai

Verma²,

Sharma³

et al. 2011

Journal of Alloys and Compounds

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Section: Introductionmentioning

confidence: 99%

Structure and magnetic properties of Cd doped copper ferrite

Rai

Verma²,

Sharma³

et al. 2011

Journal of Alloys and Compounds

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“…Actually, it is known that the electron hopping between Fe 2þ and Fe 3þ ions generally occurs in NZFO, and it also contributes to the permittivity of the ferrites ceramics based on the inhomogeneous conductivity. [30][31][32][33][34] It implies that the permittivity of the composite film will be attributed to the hybridization of both permittivities of the two constituent phases. In the concept of an effective hybrid dielectric model, the permittivity of the composite can be analysed using Kirkpatrick's compound law 35 f NZFO e NZFO Àe…”

Section: Resultsmentioning

confidence: 99%

Percolative multi-susceptible PVDF/NZFO composite films with triply controlled high dielectric and magnetic properties

Zhao

Gong

Wong

et al. 2018

Journal of Applied Physics

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Flexible multi-field susceptible films with remarkable properties and high data storage characteristics are promising in modern electronics. In this work, the percolative Ni0.5Zn0.5Fe2O4 (NZFO)/polyvinylidene fluoride (PVDF) composite films with both high permittivity and significant magnetic properties are prepared by dip coating on ITO/glass substrates. The highest permittivity of 74 is achieved with the NZFO volume ratio close to the percolation threshold, which is 20 times higher than that of pure PVDF. Meanwhile, the dielectric loss is kept below 0.1. The saturation and remanent magnetizations of composite films are 42.04 and 5.70 emu/g and the permeability is ∼3.105, reaching 60%–80% of those in the single phase NZFO. Detailed analysis shows that the high permittivity of the composite film is triply controlled simultaneously by the intrinsic characteristic of the PVDF phase, Kirkpatrick's hybridization model and microcapacitor behavior. It will be of broad interest to control both high dielectric and magnetic properties at the same time of many other flexible and susceptible storage devices.

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“…Ferrites nanomaterials are of great importance because of its optical, electrical and magnetic properties, which makes it useful materials for various scientific and industrial applications such as flexible recording media, superconductors, and magnetic refrigerator [13]. On the other hand, there several factors affect on electrical and dielectric properties of ferrites such as preparation technique, sintering (temperature, atmosphere& time) and chemical composition [14][15][16][17]. Moreover, it is interesting to investigate electrical and dielectric properties of nano-crystalline copper and substituted copper ferrite.…”

Section: Introductionmentioning

confidence: 99%

Impact of Chromium Doping on Structural, Optical, Magnetic and Electrical Properties of Nano-Copper Ferrite

GAD¹,

MOUSTAFA²,

AZAB³

et al. 2020

JOR

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Nanoparticles copper ferrites doped with chromium CuCrxFe2- xO4 (0≤x≤ 0.25) were prepared using sol-gel auto combustion. Analysis of XRD revealed that the samples crystallized in single phase tetragonal CuFe2O4 structure. Results of Rietveld refinement using Full proff program showed that the lattice parameter a increased, lattice parameter c, the unit cell volume and tetragonal distortion decreased with increasing Cr3+ concentration. A cation distribution ensured that a system (CuCrFeO4) is completely inverse and distorted. In addition, crystallite size increased with the increase of Cr3+content.Furthermore, optical energy band gap of the obtained spinel ferrite decreased from 2.441eV to 2.228 eV with the increase of Cr. Results of magnetic properties indicated that the saturation magnetization decreased from 24.1 to18.3 emu/g with Cr increment, due to a lower magnetic moment of Cr3+ ion (3mB) than that of Fe3+ ion (5mB).Coercivity decreases with increasing Cr-concentration can be attributed to the reduction in magnetocrystalline anisotropy (K) where, chromium ferrite has negative magnetocrystalline anisotropy. Squareness ratio decreased continuously with Cr content, which it displayed that the materials exhibited to soft magnetic properties. Dielectric properties were analyzed in frequency range (0.1-7MHz) at different temperatures (50- 150ºC).From electrical measurements, it was found that έ decreased at lower frequency, become nearly constant at higher frequencies for all samples and increased with increasing temperature. έ was found to increase with increasing Cr because the Cr is reducing the hopping probabilities across the grain boundaries. . Also, it was found that activation energy ΔE decreased with increasing Cr concentration.

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Dielectric properties of polycrystalline Cu–Zn ferrites at microwave frequencies

Cited by 10 publications

References 14 publications

Structure and magnetic properties of Cd doped copper ferrite

Structure and magnetic properties of Cd doped copper ferrite

Percolative multi-susceptible PVDF/NZFO composite films with triply controlled high dielectric and magnetic properties

Impact of Chromium Doping on Structural, Optical, Magnetic and Electrical Properties of Nano-Copper Ferrite

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